diff --git a/docs/待决策.md b/docs/待决策.md
index 63751f4..8c41310 100644
--- a/docs/待决策.md
+++ b/docs/待决策.md
@@ -298,7 +298,11 @@
 #### DEC-260628-04 消息级溯源 P2 切读
 - **决策**:✅ b 一次性切读(保留原表数据不删)
 - **记录**:读写路径从 `ai_conversations.messages` 切到 `ai_messages` 表,原列保留
-- **状态**:🟢 已决·待推进
+- **核验(2026-06-28)**:✅ 全部已完成——
+  - 写路径:`save_conversation` 已全量重写 ai_messages
+  - 读路径:`ai_conversation_switch`/`ai_conversation_export`/`remote_bridge::route_load_messages` 优先读 ai_messages,表空时 fallback 旧 JSON(老库兼容)
+  - 最后一处补全:`knowledge_inject::extract_knowledge_from_conversation` 也切到 ai_messages
+- **状态**:✅ 已决·已实施
 
 #### DEC-260628-05 SMELL-P1-6 String→newtype
 - **决策**:✅ b 路线(仅 Rust 内部 newtype)
diff --git a/src-tauri/src/commands/ai/knowledge_inject.rs b/src-tauri/src/commands/ai/knowledge_inject.rs
index 450edd5..7206a94 100644
--- a/src-tauri/src/commands/ai/knowledge_inject.rs
+++ b/src-tauri/src/commands/ai/knowledge_inject.rs
@@ -12,7 +12,7 @@ use df_ai::provider::{ChatMessage, CompletionRequest, LlmProvider, MessageRole};
 use df_ai::router::{
     select_model_id, Modality, TaskRequirements,
 };
-use df_storage::crud::{AiConversationRepo, KnowledgeRepo};
+use df_storage::crud::{AiConversationRepo, AiMessageRepo, KnowledgeRepo};
 use df_storage::db::Database;
 use df_storage::models::{AiProviderRecord, KnowledgeRecord};
 
@@ -566,12 +566,21 @@ async fn extract_knowledge_from_conversation(
         .filter(|t| !t.trim().is_empty())
         .unwrap_or_else(|| "未命名对话".to_string());
 
-    let messages: Vec<ChatMessage> = match serde_json::from_str(&conv.messages) {
-        Ok(v) => v,
-        Err(e) => {
-            tracing::warn!(error = %e, "[ai] 对话消息 JSON 解析失败,降级空消息(知识提炼跳过)");
-            Vec::new()
+    // 消息读取:优先 ai_messages 表(消息拆分存储真相源),表空时 fallback 旧 messages JSON 列(老库兼容)
+    let msg_repo = AiMessageRepo::new(db);
+    let records = msg_repo.list_by_conversation(conv_id).await.unwrap_or_default();
+    let messages: Vec<ChatMessage> = if !records.is_empty() {
+        records.iter().map(crate::commands::ai::commands::record_to_message).collect()
+    } else {
+        // 老库未迁移或坏数据:回退旧 messages JSON 列(与 ai_conversation_switch 同一兼容路径)
+        let has_legacy = conv.messages != "[]" && !conv.messages.is_empty();
+        if has_legacy {
+            tracing::warn!(
+                conv_id,
+                "[KNOWLEDGE-EXTRACT] ai_messages 表为空,回退旧 messages JSON 列(老库兼容)"
+            );
         }
+        serde_json::from_str(&conv.messages).unwrap_or_default()
     };
     // 过滤 user/assistant,取最后 6 条
     let recent: Vec<&ChatMessage> = messages