diff --git a/easyflow-ui-admin/app/src/views/ai/chat/index.vue b/easyflow-ui-admin/app/src/views/ai/chat/index.vue
index 08f9457..f56effb 100644
--- a/easyflow-ui-admin/app/src/views/ai/chat/index.vue
+++ b/easyflow-ui-admin/app/src/views/ai/chat/index.vue
@@ -380,9 +380,22 @@ async function fetchAssistants() {
       raw: item,
       value: String(item.id),
     }));
+    await selectDefaultAssistantIfNeeded();
   }
 }
 
+async function selectDefaultAssistantIfNeeded() {
+  if (
+    currentSessionId.value ||
+    currentSession.value?.sessionId ||
+    currentAssistantId.value ||
+    assistants.value.length === 0
+  ) {
+    return;
+  }
+  await handleAssistantChange(assistants.value[0]?.value);
+}
+
 async function fetchKnowledgeOptions() {
   loadingKnowledgeOptions.value = true;
   const [, res] = await tryit(api.get)('/api/v1/documentCollection/list', {