diff --git a/src/modules/admin-ai-chat/admin-ai-chat.service.ts b/src/modules/admin-ai-chat/admin-ai-chat.service.ts
index 11762f7..8a5cb85 100644
--- a/src/modules/admin-ai-chat/admin-ai-chat.service.ts
+++ b/src/modules/admin-ai-chat/admin-ai-chat.service.ts
@@ -3,7 +3,6 @@ import type { AiChatDto } from './dto/ai-chat.dto';
 
 const HERMES_API_URL = 'http://10.2.0.7:8642/v1/chat/completions';
 const HERMES_API_KEY = 'zhixi-hermes-key-2026';
-const SYSTEM_PROMPT = '你是知习管理后台的 AI 任务助理，帮助管理员处理日常任务、解答问题。请用简洁专业的中文回复。';
 
 @Injectable()
 export class AdminAiChatService {
@@ -12,14 +11,7 @@ export class AdminAiChatService {
   constructor() {}
 
   async chat(dto: AiChatDto) {
-    const systemMessages = dto.messages.filter(m => m.role === 'system');
-    const hasSystemPrompt = systemMessages.length > 0;
-
-    const messages = hasSystemPrompt
-      ? dto.messages
-      : [{ role: 'system' as const, content: SYSTEM_PROMPT }, ...dto.messages];
-
-    return await this.callHermes(messages);
+    return await this.callHermes(dto.messages);
   }
 
   private async callHermes(messages: Array<{ role: string; content: string }>) {