diff --git a/src/modules/rag-chat/rag-chat.controller.ts b/src/modules/rag-chat/rag-chat.controller.ts
index 2a98c0a..6a2f1ee 100644
--- a/src/modules/rag-chat/rag-chat.controller.ts
+++ b/src/modules/rag-chat/rag-chat.controller.ts
@@ -38,7 +38,7 @@ export class RagChatController {
   @Post('sessions/:id/stream')
   @ApiOperation({ summary: '发送消息（SSE 流式，支持思考过程）' })
   async sendMessageStream(@CurrentUser() user: UserPayload, @Param('id') id: string, @Body() dto: { content: string }, @Res() res: Response) {
-    res.setHeader('Content-Type', 'text/event-stream');
+    res.setHeader('Content-Type', 'text/event-stream; charset=utf-8');
     res.setHeader('Cache-Control', 'no-cache');
     res.setHeader('Connection', 'keep-alive');
     res.setHeader('X-Accel-Buffering', 'no');