diff --git a/backend/ai-core/internal/background/thinker.go b/backend/ai-core/internal/background/thinker.go
index f17e3d2..d242232 100644
--- a/backend/ai-core/internal/background/thinker.go
+++ b/backend/ai-core/internal/background/thinker.go
@@ -1064,6 +1064,17 @@ func (t *Thinker) performThink(triggerReason string) {
 
 	log.Printf("[后台思考] 开始思考周期 (触发原因=%s, 计数=%d)...", triggerReason, currentCount)
 
+	// 0. 让步于前台——如果用户最近有活动（非post_chat），跳过本次思考。
+	if triggerReason != "post_chat" {
+		t.mu.Lock()
+		sinceLastUser := time.Since(t.lastUserMessage)
+		t.mu.Unlock()
+		if sinceLastUser < 10*time.Second {
+			log.Printf("[后台思考] 用户 %v 前有活动，让步于前台回复，跳过思考", sinceLastUser.Round(time.Second))
+			return
+		}
+	}
+
 	// 1. 加载人格配置
 	personaConfig, err := t.personaLoader.Get("cyrene")
 	if err != nil {