diff --git a/src/components/chat-toolbar/chat-toolbar.tsx b/src/components/chat-toolbar/chat-toolbar.tsx
index 5c4999c17e557515a4efdb67d7d38a5a226f07bf..7b85d50e8b87afec69a2820239e477e90b458f65 100644
--- a/src/components/chat-toolbar/chat-toolbar.tsx
+++ b/src/components/chat-toolbar/chat-toolbar.tsx
@@ -95,6 +95,7 @@ export const ChatToolbar = (props: ChatToolbarProps) => {
         {
           label: '新建对话',
           title: '新建对话',
+          hidden: props.controller.opts.mode !== 'TOPIC',
           icon: () => {
             return <NewDialogueSvg />;
           },
diff --git a/src/controller/ai-topic/ai-topic.controller.ts b/src/controller/ai-topic/ai-topic.controller.ts
index cdf4914b16d8bf177f94598fd587b2790603555d..393f64cb7e10fd68b6423d11cf9189c15a5cd052 100644
--- a/src/controller/ai-topic/ai-topic.controller.ts
+++ b/src/controller/ai-topic/ai-topic.controller.ts
@@ -29,9 +29,9 @@ export class AiTopicController {
    *
    * @author tony001
    * @date 2025-02-24 16:02:44
-   * @type {(Signal<ITopic | null>)}
+   * @type {(Signal<ITopic | undefined>)}
    */
-  readonly activedTopic: Signal<ITopic | null> = signal(null);
+  readonly activedTopic: Signal<ITopic | undefined> = signal(undefined);
 
   /**
    * 当前话题配置备份
diff --git a/src/controller/chat/chat.controller.ts b/src/controller/chat/chat.controller.ts
index 9a750a57dd33b2dc26837442e215bfb803a54fc8..1626f999ebbd2d5e3125cb310df2e5b252228c2e 100644
--- a/src/controller/chat/chat.controller.ts
+++ b/src/controller/chat/chat.controller.ts
@@ -159,6 +159,8 @@ export class ChatController {
         },
       });
       await this.aiTopic.updateCurrentTopic(topicOptions);
+    } else {
+      this.aiTopic.activedTopic.value = undefined;
     }
 
     Object.assign(chatOptions, {