diff --git a/src/command/handlers/rename_topic.rs b/src/command/handlers/rename_topic.rs
index 0db12b7..6d83d4f 100644
--- a/src/command/handlers/rename_topic.rs
+++ b/src/command/handlers/rename_topic.rs
@@ -75,10 +75,15 @@ async fn handle_rename_topic(
             CommandError::new("TOPIC_NOT_FOUND", format!("Topic not found: {}", topic_id))
         })?;
 
-    let old_title = topic.title.clone();
+    let old_display = topic
+        .description
+        .as_deref()
+        .filter(|s| !s.is_empty())
+        .unwrap_or(&topic.title)
+        .to_string();
 
     // 标题未变化时直接返回当前列表，避免无意义写入
-    if old_title == trimmed_title {
+    if old_display == trimmed_title {
         let topics = handler
             .store
             .list_topics(session_id)
@@ -98,10 +103,10 @@ async fn handle_rename_topic(
             .with_metadata("session_id", session_id));
     }
 
-    // 执行重命名（存储层方法已存在）
+    // 执行重命名：更新 description（显示字段），保留 title 作为内部标识
     handler
         .store
-        .update_topic_title(&topic_id, trimmed_title)
+        .update_topic_description(&topic_id, trimmed_title)
         .map_err(|e| CommandError::new("RENAME_TOPIC_ERROR", e.to_string()))?;
 
     // 查询更新后的话题列表，返回给前端刷新侧边栏
@@ -114,7 +119,7 @@ async fn handle_rename_topic(
     let topic_summaries_json = serde_json::to_string(&topic_summaries)
         .map_err(|e| CommandError::new("SERIALIZE_ERROR", e.to_string()))?;
 
-    let message = format!("✓ 已重命名话题: {} → {}", old_title, trimmed_title);
+    let message = format!("✓ 已重命名话题: {} → {}", old_display, trimmed_title);
 
     Ok(CommandResponse::success(ctx.request_id)
         .with_message(MessageKind::Notification, &message)
@@ -165,9 +170,10 @@ mod tests {
         );
         assert!(resp.metadata.contains_key("topics"));
 
-        // 验证存储层已更新
+        // 验证存储层已更新 description（显示字段），title 保持原内部标识
         let updated = store.get_topic(&topic.id).unwrap().unwrap();
-        assert_eq!(updated.title, "new title");
+        assert_eq!(updated.title, "old title");
+        assert_eq!(updated.description.as_deref(), Some("new title"));
     }
 
     #[tokio::test]
@@ -222,6 +228,7 @@ mod tests {
         let store = handler.store.clone();
 
         let session = store.create_session("test_channel", Some("test")).unwrap();
+        // description=None，当前显示值 fallback 到 title
         let topic = store.create_topic(&session.id, "same title", None).unwrap();
         let original_updated_at = store.get_topic(&topic.id).unwrap().unwrap().updated_at;
 
@@ -244,6 +251,38 @@ mod tests {
         assert_eq!(after.updated_at, original_updated_at);
     }
 
+    #[tokio::test]
+    async fn test_rename_topic_compares_against_description_when_present() {
+        // 有 description 时，"未变化"比较应基于 description 而非 title
+        let handler = create_test_handler();
+        let store = handler.store.clone();
+
+        let session = store.create_session("test_channel", Some("test")).unwrap();
+        // title 是内部标识，description 是显示值
+        let topic = store
+            .create_topic(&session.id, "topic_internal_id", Some("AI 生成的摘要"))
+            .unwrap();
+        let original_updated_at = store.get_topic(&topic.id).unwrap().unwrap().updated_at;
+
+        tokio::time::sleep(std::time::Duration::from_secs(1)).await;
+
+        let ctx = CommandContext::new("test", "test_channel")
+            .with_session_id(&session.id)
+            .with_chat_id(&session.id);
+        // 提交与 description 相同的值（不是 title），应跳过写入
+        let cmd = Command::RenameTopic {
+            topic_id: topic.id.clone(),
+            title: "AI 生成的摘要".to_string(),
+        };
+
+        let result = handler.handle(cmd, ctx).await;
+        assert!(result.is_ok());
+
+        let after = store.get_topic(&topic.id).unwrap().unwrap();
+        assert_eq!(after.updated_at, original_updated_at);
+        assert_eq!(after.title, "topic_internal_id");
+    }
+
     #[test]
     fn test_can_handle() {
         let handler = create_test_handler();
diff --git a/web/src/components/Sidebar/TopicList.tsx b/web/src/components/Sidebar/TopicList.tsx
index e954df2..752b033 100644
--- a/web/src/components/Sidebar/TopicList.tsx
+++ b/web/src/components/Sidebar/TopicList.tsx
@@ -93,7 +93,8 @@ export function TopicList({
   const startEdit = useCallback((topic: Topic) => {
     setConfirmDeleteId(null);
     setEditingTopicId(topic.id);
-    setEditingTitle(topic.title);
+    // 预填当前显示值（description 优先，与列表显示逻辑一致）
+    setEditingTitle(topic.description || topic.title);
   }, []);
 
   const cancelEdit = useCallback(() => {