diff --git a/Batch.md b/Batch.md
index 32598d0..7814011 100644
--- a/Batch.md
+++ b/Batch.md
@@ -437,7 +437,7 @@
 
 ### 数据层 + Git worktree 隔离 + 并行执行
 
-- **提交**: `当前待提交`
+- **提交**: `ae6d3d0`
 
 | # | 任务 | 文件 |
 |---|------|------|
diff --git a/Cargo.lock b/Cargo.lock
index c0db3f3..de46f22 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -885,6 +885,7 @@ dependencies = [
  "reqwest 0.12.28",
  "serde",
  "serde_json",
+ "tempfile",
  "tokio",
  "tracing",
 ]
diff --git a/crates/df-ai/Cargo.toml b/crates/df-ai/Cargo.toml
index 26e4f4b..c4b4079 100644
--- a/crates/df-ai/Cargo.toml
+++ b/crates/df-ai/Cargo.toml
@@ -18,3 +18,6 @@ reqwest = { version = "0.12", features = ["stream", "json"] }
 futures = "0.3"
 eventsource-stream = "0.2"
 rand = "0.8"
+
+[dev-dependencies]
+tempfile = "3"
diff --git a/crates/df-ai/src/git_worktree.rs b/crates/df-ai/src/git_worktree.rs
new file mode 100644
index 0000000..b4212e1
--- /dev/null
+++ b/crates/df-ai/src/git_worktree.rs
@@ -0,0 +1,542 @@
+//! Git worktree 生命周期管理 — 多 Agent 并行执行的文件隔离基础
+//!
+//! 设计依据:docs/02-架构设计/专项设计/多Agent并行执行与仲裁合并设计-2026-07-01.md §4.2
+//!
+//! 每个 SubTask 创建独立 worktree(git worktree add + 新分支),
+//! 写操作天然隔离。合并时用 git merge-tree 预检 + git merge 实际合并。
+
+use std::path::{Path, PathBuf};
+use std::process::Command;
+
+/// worktree 管理错误
+#[derive(Debug)]
+pub enum WorktreeError {
+    /// Git 命令执行失败(stdout/stderr 含错误信息)
+    GitFailed(String),
+    /// 工程根目录无 .git(非 Git 工程,应降级串行)
+    NotGitRepo,
+    /// worktree 目录已存在(可能上次未清理)
+    AlreadyExists(PathBuf),
+}
+
+impl std::fmt::Display for WorktreeError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::GitFailed(msg) => write!(f, "Git 命令失败: {}", msg),
+            Self::NotGitRepo => write!(f, "非 Git 工程(无 .git 目录)"),
+            Self::AlreadyExists(p) => write!(f, "worktree 目录已存在: {}", p.display()),
+        }
+    }
+}
+
+impl std::error::Error for WorktreeError {}
+
+/// worktree 创建结果
+#[derive(Debug, Clone)]
+pub struct WorktreeHandle {
+    /// worktree 物理路径(SubTask 工具操作的 cwd)
+    pub path: PathBuf,
+    /// worktree 对应的分支名(merge 时用)
+    pub branch: String,
+    /// 所属 Plan id(清理时按 plan 批量)
+    pub plan_id: String,
+    /// SubTask id
+    pub subtask_id: String,
+}
+
+/// 在指定工程根目录下创建 SubTask 专属 worktree。
+///
+/// - `project_root`: 工程根目录(含 .git)
+/// - `plan_id`: 所属 Plan id
+/// - `subtask_id`: SubTask id
+/// - `base_branch`: fork 基点分支(plan 分支或主分支)
+///
+/// 返回 WorktreeHandle(path + branch)。
+/// worktree 路径:`{project_root}/.devflow/wt/{plan_id}/{subtask_id}`
+/// 分支名:`subtask/{plan_id}/{subtask_id}`
+pub fn create_worktree(
+    project_root: &Path,
+    plan_id: &str,
+    subtask_id: &str,
+    base_branch: &str,
+) -> Result<WorktreeHandle, WorktreeError> {
+    if !project_root.join(".git").exists() {
+        return Err(WorktreeError::NotGitRepo);
+    }
+
+    let wt_path = project_root.join(".devflow/wt").join(plan_id).join(subtask_id);
+    if wt_path.exists() {
+        return Err(WorktreeError::AlreadyExists(wt_path));
+    }
+
+    let branch = format!("subtask/{}/{}", plan_id, subtask_id);
+
+    // git worktree add <path> -b <branch> <base_branch>
+    let output = Command::new("git")
+        .args([
+            "worktree",
+            "add",
+            wt_path.to_str().unwrap_or(""),
+            "-b",
+            &branch,
+            base_branch,
+        ])
+        .current_dir(project_root)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git worktree add 执行失败: {}", e)))?;
+
+    if !output.status.success() {
+        let stderr = String::from_utf8_lossy(&output.stderr);
+        return Err(WorktreeError::GitFailed(format!(
+            "git worktree add 失败: {}",
+            stderr.trim()
+        )));
+    }
+
+    Ok(WorktreeHandle {
+        path: wt_path,
+        branch,
+        plan_id: plan_id.to_string(),
+        subtask_id: subtask_id.to_string(),
+    })
+}
+
+/// 在 worktree 内提交所有改动(git add -A + git commit)。
+///
+/// - `wt_path`: worktree 物理路径
+/// - `message`: commit 消息
+pub fn commit_worktree(wt_path: &Path, message: &str) -> Result<(), WorktreeError> {
+    // git add -A
+    let add = Command::new("git")
+        .args(["add", "-A"])
+        .current_dir(wt_path)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git add 失败: {}", e)))?;
+    if !add.status.success() {
+        return Err(WorktreeError::GitFailed(format!(
+            "git add 失败: {}",
+            String::from_utf8_lossy(&add.stderr).trim()
+        )));
+    }
+
+    // git commit -m (允许空提交,--allow-empty 防无改动时报错)
+    let commit = Command::new("git")
+        .args(["commit", "--allow-empty", "-m", message])
+        .current_dir(wt_path)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git commit 失败: {}", e)))?;
+    if !commit.status.success() {
+        // commit 失败可能因无 user.email 配置(测试环境),尝试自动配
+        let stderr = String::from_utf8_lossy(&commit.stderr);
+        if stderr.contains("user.email") || stderr.contains("user.name") {
+            // 降级:设置临时配置后重试
+            Command::new("git")
+                .args(["config", "user.email", "devflow@ai.local"])
+                .current_dir(wt_path)
+                .output()
+                .ok();
+            Command::new("git")
+                .args(["config", "user.name", "DevFlow Agent"])
+                .current_dir(wt_path)
+                .output()
+                .ok();
+            let retry = Command::new("git")
+                .args(["commit", "--allow-empty", "-m", message])
+                .current_dir(wt_path)
+                .output()
+                .map_err(|e| WorktreeError::GitFailed(format!("git commit 重试失败: {}", e)))?;
+            if !retry.status.success() {
+                return Err(WorktreeError::GitFailed(format!(
+                    "git commit 重试仍失败: {}",
+                    String::from_utf8_lossy(&retry.stderr).trim()
+                )));
+            }
+            return Ok(());
+        }
+        return Err(WorktreeError::GitFailed(format!("git commit 失败: {}", stderr.trim())));
+    }
+
+    Ok(())
+}
+
+/// 将 SubTask 分支 merge 到 plan 分支(在 plan worktree 内执行)。
+///
+/// 返回 Ok(true) 表示有改动被合并,Ok(false) 表示无改动(空分支)。
+/// 返回 Err 表示 merge 冲突。
+pub fn merge_branch(
+    plan_wt_path: &Path,
+    subtask_branch: &str,
+) -> Result<MergeResult, WorktreeError> {
+    // 先用 merge-tree 预检
+    let precheck = Command::new("git")
+        .args(["merge-tree", "--write-tree", "--messages", "HEAD", subtask_branch])
+        .current_dir(plan_wt_path)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git merge-tree 失败: {}", e)))?;
+
+    // merge-tree --write-tree 成功(exit 0)= 无冲突可自动合并;
+    // 非0(冲突)且 stdout 非空 = 有冲突
+    if !precheck.status.success() {
+        let stdout = String::from_utf8_lossy(&precheck.stdout);
+        if !stdout.is_empty() {
+            return Ok(MergeResult::Conflict {
+                branch: subtask_branch.to_string(),
+                details: stdout.to_string(),
+            });
+        }
+    }
+
+    // 无冲突,执行实际 merge
+    let merge = Command::new("git")
+        .args(["merge", "--no-edit", subtask_branch])
+        .current_dir(plan_wt_path)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git merge 失败: {}", e)))?;
+
+    if !merge.status.success() {
+        // merge 冲突(git merge 返回非0)
+        let stderr = String::from_utf8_lossy(&merge.stderr);
+        let stdout = String::from_utf8_lossy(&merge.stdout);
+        // abort 部分合并状态(防 worktree 处于 conflicted 状态)
+        let _ = Command::new("git")
+            .args(["merge", "--abort"])
+            .current_dir(plan_wt_path)
+            .output();
+        return Ok(MergeResult::Conflict {
+            branch: subtask_branch.to_string(),
+            details: format!("{}\n{}", stdout, stderr),
+        });
+    }
+
+    Ok(MergeResult::Clean)
+}
+
+/// merge 结果
+#[derive(Debug, Clone)]
+pub enum MergeResult {
+    /// 干净合并(无冲突)
+    Clean,
+    /// 合并冲突(details 含 conflict 信息)
+    Conflict { branch: String, details: String },
+}
+
+/// 清理单个 SubTask 的 worktree(git worktree remove --force + 删分支)。
+pub fn remove_worktree(project_root: &Path, handle: &WorktreeHandle) -> Result<(), WorktreeError> {
+    // git worktree remove --force <path>
+    let _ = Command::new("git")
+        .args([
+            "worktree",
+            "remove",
+            "--force",
+            handle.path.to_str().unwrap_or(""),
+        ])
+        .current_dir(project_root)
+        .output();
+
+    // 删除分支(-D 强制,已 merge 的分支正常删,未 merge 的也删)
+    let _ = Command::new("git")
+        .args(["branch", "-D", &handle.branch])
+        .current_dir(project_root)
+        .output();
+
+    Ok(())
+}
+
+/// 清理某 Plan 的所有 worktree(Plan 完成/失败/取消时批量清理)。
+pub fn remove_plan_worktrees(project_root: &Path, plan_id: &str) -> Result<(), WorktreeError> {
+    let plan_wt_dir = project_root.join(".devflow/wt").join(plan_id);
+    if !plan_wt_dir.exists() {
+        return Ok(());
+    }
+
+    // git worktree list 获取该 plan 下所有 worktree
+    let list = Command::new("git")
+        .args(["worktree", "list", "--porcelain"])
+        .current_dir(project_root)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git worktree list 失败: {}", e)))?;
+
+    let list_str = String::from_utf8_lossy(&list.stdout);
+    for line in list_str.lines() {
+        if let Some(path_str) = line.strip_prefix("worktree ") {
+            let path = PathBuf::from(path_str);
+            // 仅清理属于本 plan 的 worktree
+            if path.starts_with(&plan_wt_dir) {
+                let _ = Command::new("git")
+                    .args(["worktree", "remove", "--force", path_str])
+                    .current_dir(project_root)
+                    .output();
+            }
+        }
+    }
+
+    // 删除该 plan 的所有子任务分支
+    let branches = Command::new("git")
+        .args(["branch", "--list", &format!("subtask/{}/*", plan_id)])
+        .current_dir(project_root)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git branch --list 失败: {}", e)))?;
+
+    let branches_str = String::from_utf8_lossy(&branches.stdout);
+    for line in branches_str.lines() {
+        let branch = line.trim();
+        if !branch.is_empty() {
+            let _ = Command::new("git")
+                .args(["branch", "-D", branch])
+                .current_dir(project_root)
+                .output();
+        }
+    }
+
+    // 清理空目录
+    let _ = std::fs::remove_dir_all(&plan_wt_dir);
+
+    Ok(())
+}
+
+/// 检测工程是否为 Git 仓库(有 .git 目录)。
+pub fn is_git_repo(project_root: &Path) -> bool {
+    project_root.join(".git").exists()
+}
+
+/// 获取工程当前分支名(用于作为 plan worktree 的 fork 基点)。
+pub fn current_branch(project_root: &Path) -> Result<String, WorktreeError> {
+    let output = Command::new("git")
+        .args(["rev-parse", "--abbrev-ref", "HEAD"])
+        .current_dir(project_root)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git rev-parse 失败: {}", e)))?;
+
+    if !output.status.success() {
+        return Err(WorktreeError::GitFailed(
+            String::from_utf8_lossy(&output.stderr).trim().to_string(),
+        ));
+    }
+
+    Ok(String::from_utf8_lossy(&output.stdout).trim().to_string())
+}
+
+/// 创建 Plan worktree(Plan 级工作分支,所有 SubTask 分支 merge 到这里)。
+///
+/// 返回 (plan_worktree_path, plan_branch)。
+pub fn create_plan_worktree(
+    project_root: &Path,
+    plan_id: &str,
+) -> Result<(PathBuf, String), WorktreeError> {
+    if !is_git_repo(project_root) {
+        return Err(WorktreeError::NotGitRepo);
+    }
+
+    let base = current_branch(project_root)?;
+    let plan_branch = format!("plan/{}", plan_id);
+    let plan_wt_path = project_root.join(".devflow/wt").join(plan_id);
+
+    if plan_wt_path.exists() {
+        return Err(WorktreeError::AlreadyExists(plan_wt_path));
+    }
+
+    let output = Command::new("git")
+        .args([
+            "worktree",
+            "add",
+            plan_wt_path.to_str().unwrap_or(""),
+            "-b",
+            &plan_branch,
+            &base,
+        ])
+        .current_dir(project_root)
+        .output()
+        .map_err(|e| WorktreeError::GitFailed(format!("git worktree add(plan) 失败: {}", e)))?;
+
+    if !output.status.success() {
+        return Err(WorktreeError::GitFailed(format!(
+            "git worktree add(plan) 失败: {}",
+            String::from_utf8_lossy(&output.stderr).trim()
+        )));
+    }
+
+    Ok((plan_wt_path, plan_branch))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// 创建临时 Git 仓库 + 初始 commit
+    fn setup_repo() -> tempfile::TempDir {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path();
+
+        Command::new("git").args(["init"]).current_dir(path).output().unwrap();
+        Command::new("git").args(["config", "user.email", "test@test.com"]).current_dir(path).output().unwrap();
+        Command::new("git").args(["config", "user.name", "test"]).current_dir(path).output().unwrap();
+
+        std::fs::write(path.join("main.rs"), "fn main() {}\n").unwrap();
+        Command::new("git").args(["add", "."]).current_dir(path).output().unwrap();
+        Command::new("git").args(["commit", "-m", "init"]).current_dir(path).output().unwrap();
+
+        dir
+    }
+
+    #[test]
+    fn wt_01_create_and_isolate() {
+        let repo = setup_repo();
+        let root = repo.path();
+        let base = current_branch(root).unwrap();
+
+        let handle = create_worktree(root, "plan-test", "A", &base).unwrap();
+        assert!(handle.path.exists(), "worktree 目录应存在");
+        assert_eq!(handle.branch, "subtask/plan-test/A");
+
+        // 在 worktree 内写文件
+        std::fs::write(handle.path.join("new_a.rs"), "// A 的改动").unwrap();
+        // 主目录不应有此文件
+        assert!(!root.join("new_a.rs").exists(), "主目录不应有 A 的改动");
+
+        // 清理
+        remove_worktree(root, &handle).unwrap();
+    }
+
+    #[test]
+    fn wt_02_parallel_isolation() {
+        let repo = setup_repo();
+        let root = repo.path();
+
+        let plan_wt = create_plan_worktree(root, "plan-iso").unwrap();
+        let plan_branch = plan_wt.1;
+
+        let a = create_worktree(root, "plan-iso", "A", &plan_branch).unwrap();
+        let b = create_worktree(root, "plan-iso", "B", &plan_branch).unwrap();
+
+        // A 写 new_a.rs
+        std::fs::write(a.path.join("new_a.rs"), "// A").unwrap();
+        // B 写 new_b.rs
+        std::fs::write(b.path.join("new_b.rs"), "// B").unwrap();
+
+        // A 的 worktree 不应有 B 的文件
+        assert!(!a.path.join("new_b.rs").exists(), "A 不应看到 B 的改动");
+        // B 的 worktree 不应有 A 的文件
+        assert!(!b.path.join("new_a.rs").exists(), "B 不应看到 A 的改动");
+
+        remove_plan_worktrees(root, "plan-iso").unwrap();
+    }
+
+    #[test]
+    fn wt_03_commit_in_worktree() {
+        let repo = setup_repo();
+        let root = repo.path();
+
+        let plan_wt = create_plan_worktree(root, "plan-commit").unwrap();
+        let a = create_worktree(root, "plan-commit", "A", &plan_wt.1).unwrap();
+
+        // 写文件 + commit
+        std::fs::write(a.path.join("feature.rs"), "pub fn feature() {}").unwrap();
+        commit_worktree(&a.path, "Add feature").unwrap();
+
+        // 验证分支有新 commit
+        let log = Command::new("git")
+            .args(["log", "--oneline", "-1"])
+            .current_dir(&a.path)
+            .output()
+            .unwrap();
+        let log_str = String::from_utf8_lossy(&log.stdout);
+        assert!(log_str.contains("Add feature"), "commit 消息应在 log 中");
+
+        remove_plan_worktrees(root, "plan-commit").unwrap();
+    }
+
+    #[test]
+    fn wt_04_merge_no_conflict() {
+        let repo = setup_repo();
+        let root = repo.path();
+
+        let plan_wt = create_plan_worktree(root, "plan-merge").unwrap();
+        let plan_wt_path = plan_wt.0.clone();
+        let plan_branch = plan_wt.1;
+
+        // A 改 file_a.rs, B 改 file_b.rs(不同文件,无冲突)
+        let a = create_worktree(root, "plan-merge", "A", &plan_branch).unwrap();
+        std::fs::write(a.path.join("file_a.rs"), "// A").unwrap();
+        commit_worktree(&a.path, "A changes").unwrap();
+
+        let b = create_worktree(root, "plan-merge", "B", &plan_branch).unwrap();
+        std::fs::write(b.path.join("file_b.rs"), "// B").unwrap();
+        commit_worktree(&b.path, "B changes").unwrap();
+
+        // merge A → plan
+        let result_a = merge_branch(&plan_wt_path, &a.branch).unwrap();
+        assert!(matches!(result_a, MergeResult::Clean), "A merge 应无冲突");
+
+        // merge B → plan
+        let result_b = merge_branch(&plan_wt_path, &b.branch).unwrap();
+        assert!(matches!(result_b, MergeResult::Clean), "B merge 应无冲突");
+
+        // plan worktree 应同时有 file_a.rs 和 file_b.rs
+        assert!(plan_wt_path.join("file_a.rs").exists(), "plan 应含 A 的改动");
+        assert!(plan_wt_path.join("file_b.rs").exists(), "plan 应含 B 的改动");
+
+        remove_plan_worktrees(root, "plan-merge").unwrap();
+    }
+
+    #[test]
+    fn wt_05_merge_conflict_same_file() {
+        let repo = setup_repo();
+        let root = repo.path();
+
+        // 写一个共享文件
+        std::fs::write(root.join("shared.rs"), "line1\nline2\n").unwrap();
+        Command::new("git").args(["add", "-A"]).current_dir(root).output().unwrap();
+        Command::new("git").args(["commit", "-m", "add shared"]).current_dir(root).output().unwrap();
+
+        let plan_wt = create_plan_worktree(root, "plan-conf").unwrap();
+        let plan_wt_path = plan_wt.0.clone();
+        let plan_branch = plan_wt.1;
+
+        // A 和 B 改同一文件的同一行
+        let a = create_worktree(root, "plan-conf", "A", &plan_branch).unwrap();
+        std::fs::write(a.path.join("shared.rs"), "A_version\n").unwrap();
+        commit_worktree(&a.path, "A change shared").unwrap();
+
+        let b = create_worktree(root, "plan-conf", "B", &plan_branch).unwrap();
+        std::fs::write(b.path.join("shared.rs"), "B_version\n").unwrap();
+        commit_worktree(&b.path, "B change shared").unwrap();
+
+        // merge A → 无冲突
+        let result_a = merge_branch(&plan_wt_path, &a.branch).unwrap();
+        assert!(matches!(result_a, MergeResult::Clean), "首个 merge 应无冲突");
+
+        // merge B → 冲突
+        let result_b = merge_branch(&plan_wt_path, &b.branch).unwrap();
+        assert!(
+            matches!(result_b, MergeResult::Conflict { .. }),
+            "同文件同行改应产生冲突"
+        );
+
+        remove_plan_worktrees(root, "plan-conf").unwrap();
+    }
+
+    #[test]
+    fn wt_06_non_git_returns_error() {
+        let dir = tempfile::tempdir().unwrap();
+        // 不 init git
+        let result = create_plan_worktree(dir.path(), "plan-ng");
+        assert!(matches!(result, Err(WorktreeError::NotGitRepo)));
+    }
+
+    #[test]
+    fn wt_07_cleanup_removes_worktree() {
+        let repo = setup_repo();
+        let root = repo.path();
+
+        let plan_wt = create_plan_worktree(root, "plan-clean").unwrap();
+        let a = create_worktree(root, "plan-clean", "A", &plan_wt.1).unwrap();
+        assert!(a.path.exists());
+
+        remove_plan_worktrees(root, "plan-clean").unwrap();
+
+        // worktree 目录应被清理
+        assert!(!a.path.exists(), "worktree 目录应已清理");
+        // plan wt 目录也应被清理
+        assert!(!plan_wt.0.exists(), "plan worktree 目录应已清理");
+    }
+}
diff --git a/crates/df-ai/src/lib.rs b/crates/df-ai/src/lib.rs
index 88d93ed..065d8f0 100644
--- a/crates/df-ai/src/lib.rs
+++ b/crates/df-ai/src/lib.rs
@@ -10,6 +10,7 @@ pub mod coordinator;
 // 会话意图识别层(纯函数,不接入 agentic loop)。依据 docs/02-架构设计/构想审查/
 // 意图识别层论证-2026-06-19.md。提供 recognize / tool_subset_for / suggested_model_tier。
 // 待 Phase B+C 完成 + 模型模态管理落地后再接入 agentic loop。
+pub mod git_worktree;
 pub mod intent;
 pub mod model_fetch;
 // model_fetch 的纯逻辑子模块(URL 拼接 / 噪音过滤 / 响应反序列化),