diff --git a/src/gateway/ws.rs b/src/gateway/ws.rs
index 73234bf..7ca9543 100644
--- a/src/gateway/ws.rs
+++ b/src/gateway/ws.rs
@@ -459,12 +459,13 @@ async fn handle_inbound(
                 }
                 // 加载子智能体任务消息
                 if let Some(task_session_id) = response.metadata.get("task_session_id") {
-                    if let Err(e) = send_task_messages(&store, task_session_id, sender).await {
+                    // 提前提取 task_id，用于给历史消息打标记
+                    let task_id = response.metadata.get("task_id").cloned().unwrap_or_default();
+                    if let Err(e) = send_task_messages(&store, task_session_id, sender, Some(task_id.clone())).await {
                         tracing::warn!(error = %e, task_session_id = %task_session_id, "Failed to send task messages");
                     }
 
                     // 发送 TaskMessagesLoaded 元数据
-                    let task_id = response.metadata.get("task_id").cloned().unwrap_or_default();
                     let description = response.metadata.get("task_description").cloned().unwrap_or_default();
                     let subagent_type = response.metadata.get("task_subagent_type").cloned().unwrap_or_default();
                     let status = response.metadata.get("task_status").cloned().unwrap_or_default();
@@ -496,7 +497,7 @@ async fn handle_inbound(
                         &load_chat_channel,
                         load_chat_id,
                     );
-                    if let Err(e) = send_task_messages(&store, &session_id, sender).await {
+                    if let Err(e) = send_task_messages(&store, &session_id, sender, None).await {
                         tracing::warn!(
                             error = %e,
                             channel = %load_chat_channel,
@@ -591,13 +592,19 @@ async fn send_task_messages(
     store: &Arc<crate::storage::SessionStore>,
     session_id: &str,
     sender: &mpsc::Sender<WsOutbound>,
+    subagent_task_id: Option<String>,
 ) -> Result<(), Box<dyn std::error::Error>> {
     let messages = store.load_messages(session_id)?;
 
     tracing::info!(session_id = %session_id, message_count = messages.len(), "Sending task messages");
 
     for msg in messages {
-        let outbound = chat_message_to_ws_outbound(&msg);
+        let mut outbound = chat_message_to_ws_outbound(&msg);
+        if let Some(ref task_id) = subagent_task_id {
+            if let Some(ref mut ob) = outbound {
+                set_subagent_task_id(ob, task_id);
+            }
+        }
         if let Some(outbound) = outbound {
             let _ = sender.send(outbound).await;
         }
@@ -606,6 +613,27 @@ async fn send_task_messages(
     Ok(())
 }
 
+/// 给 WsOutbound 消息注入 subagent_task_id（仅对有该字段的变体生效）
+fn set_subagent_task_id(outbound: &mut WsOutbound, task_id: &str) {
+    match outbound {
+        WsOutbound::AssistantResponse {
+            subagent_task_id, ..
+        }
+        | WsOutbound::ToolCall {
+            subagent_task_id, ..
+        }
+        | WsOutbound::ToolResult {
+            subagent_task_id, ..
+        }
+        | WsOutbound::ToolPending {
+            subagent_task_id, ..
+        } => {
+            *subagent_task_id = Some(task_id.to_string());
+        }
+        _ => {} // 其他变体没有 subagent_task_id 字段
+    }
+}
+
 /// 将 ChatMessage 转换为 WsOutbound
 fn chat_message_to_ws_outbound(msg: &crate::bus::ChatMessage) -> Option<WsOutbound> {
     use crate::bus::message::ToolMessageState;
diff --git a/web/src/hooks/useChat.ts b/web/src/hooks/useChat.ts
index d75fb9a..c450b3a 100644
--- a/web/src/hooks/useChat.ts
+++ b/web/src/hooks/useChat.ts
@@ -251,11 +251,11 @@ export function useChat(): UseChatReturn {
         return
       }
 
-      // Route messages to sub-agent view:
-      // - Messages without subagent_task_id = loaded history, always accept
-      // - Messages with subagent_task_id = live emitter, only accept if matching
+      // Only accept messages explicitly tagged with matching subagent_task_id.
+      // History messages are now tagged by the backend (send_task_messages),
+      // and live sub-agent messages are tagged by SubAgentEmitter.
       const msgSubagentTaskId = getSubagentTaskId(message)
-      if (!msgSubagentTaskId || msgSubagentTaskId === currentSubAgentView.taskId) {
+      if (msgSubagentTaskId && msgSubagentTaskId === currentSubAgentView.taskId) {
         appendToSubAgentViewMessage(message)
       }
       return