diff --git a/backend/src/services/conversationService.ts b/backend/src/services/conversationService.ts
index 0a0940eb..ca1e9dec 100644
--- a/backend/src/services/conversationService.ts
+++ b/backend/src/services/conversationService.ts
@@ -143,7 +143,8 @@ export class ConversationService {
     // 获取系统Prompt
     const systemPrompt = agentService.getSystemPrompt(agentId);
 
-    // 获取历史消息（最近10条）
+    // 获取历史消息（最近100条，约50轮对话）
+    // DeepSeek-V3支持64K tokens，实际可容纳100-200轮对话
     const historyMessages = await prisma.message.findMany({
       where: {
         conversationId,
@@ -151,7 +152,7 @@ export class ConversationService {
       orderBy: {
         createdAt: 'desc',
       },
-      take: 10,
+      take: 100,
     });
 
     // 反转顺序（最早的在前）