diff --git a/src/channels/feishu.rs b/src/channels/feishu.rs
index 1132f2b..c311ae3 100644
--- a/src/channels/feishu.rs
+++ b/src/channels/feishu.rs
@@ -2504,6 +2504,15 @@ impl Channel for FeishuChannel {
             "open_id"
         };
 
+        // reaction 语义:仅"终态消息"成功发送后才移除 reaction。
+        // 终态 = AssistantResponse(最终响应)或 ErrorNotification(agent 异常终止的错误通知)。
+        // ToolCall 等中间过程事件不触碰 reaction——让 reaction 真实反映用户是否已收到
+        // agent 的最终产出(reaction 持续 = 尚未收到响应或错误;reaction 消失 = 已收到)。
+        // 发送失败时保留 reaction 作为异常信号;空内容不视为送达,保留 reaction。
+        let is_terminal = matches!(
+            msg.event_kind,
+            OutboundEventKind::AssistantResponse | OutboundEventKind::ErrorNotification
+        );
         let remove_reaction = async {
             self.remove_reaction_from_metadata(&msg.metadata).await;
         };
@@ -2514,7 +2523,14 @@ impl Channel for FeishuChannel {
 
             // Empty content
             if content.is_empty() {
-                remove_reaction.await;
+                // 空最终响应是异常:保留 reaction 让用户察觉,仅记录 warn。
+                // 非最终响应(如 ToolCall 空内容)本来就不触碰 reaction。
+                if is_terminal {
+                    tracing::warn!(
+                        chat_id = %msg.chat_id,
+                        "Final response has empty content, keeping reaction as anomaly signal"
+                    );
+                }
                 return Ok(());
             }
 
@@ -2526,7 +2542,10 @@ impl Channel for FeishuChannel {
                     let result = self
                         .dispatch_send(receive_id, receive_id_type, "text", content, reply_to)
                         .await;
-                    remove_reaction.await;
+                    // 仅最终响应且发送成功才移除 reaction
+                    if is_terminal && result.is_ok() {
+                        remove_reaction.await;
+                    }
                     return result;
                 }
                 MsgFormat::Post => {
@@ -2535,7 +2554,9 @@ impl Channel for FeishuChannel {
                     let result = self
                         .dispatch_send(receive_id, receive_id_type, "post", &post_body, reply_to)
                         .await;
-                    remove_reaction.await;
+                    if is_terminal && result.is_ok() {
+                        remove_reaction.await;
+                    }
                     return result;
                 }
                 MsgFormat::Interactive => {
@@ -2561,11 +2582,17 @@ impl Channel for FeishuChannel {
                                     reply_to,
                                 )
                                 .await;
-                            remove_reaction.await;
+                            // 回退成功才移除 reaction;回退失败则保留作为异常信号
+                            if is_terminal && result.is_ok() {
+                                remove_reaction.await;
+                            }
                             return result;
                         }
                     }
-                    remove_reaction.await;
+                    // 所有 chunk 成功:仅最终响应移除 reaction
+                    if is_terminal {
+                        remove_reaction.await;
+                    }
                     return Ok(());
                 }
             }
@@ -2618,19 +2645,23 @@ impl Channel for FeishuChannel {
                 Ok(()) => sent_media += 1,
                 Err(error) => {
                     tracing::warn!(error = %error, path = %path, media_type = %media_item.media_type, "Failed to send media message to Feishu");
+                    // 媒体失败:保留 reaction 作为异常信号(不调用 remove_reaction)
                     return Err(error);
                 }
             }
         }
 
         if msg.content.trim().is_empty() && sent_media == 0 {
-            remove_reaction.await;
+            // 无内容无媒体:保留 reaction 作为异常信号
             return Err(ChannelError::Other(
                 "No supported media items were sent to Feishu".to_string(),
             ));
         }
 
-        remove_reaction.await;
+        // 全部成功:仅最终响应移除 reaction
+        if is_terminal {
+            remove_reaction.await;
+        }
         Ok(())
     }
 }
diff --git a/src/channels/manager.rs b/src/channels/manager.rs
index b480b1c..5da4b35 100644
--- a/src/channels/manager.rs
+++ b/src/channels/manager.rs
@@ -26,7 +26,7 @@ impl ChannelManager {
 
         Self {
             channels: Arc::new(RwLock::new(channels)),
-            bus: MessageBus::new(100),
+            bus: MessageBus::new(256),
             websocket_channel,
         }
     }