diff --git a/backend/ai-core/internal/background/thinker.go b/backend/ai-core/internal/background/thinker.go
index c9b98d6..caea76f 100644
--- a/backend/ai-core/internal/background/thinker.go
+++ b/backend/ai-core/internal/background/thinker.go
@@ -128,6 +128,10 @@ type Thinker struct {
 	// 默认 300 秒（5 分钟），设为 0 则禁用定时触发
 	thinkInterval time.Duration
 
+	// 轻量思考（简单思考）：高频、快速模型、简单 prompt
+	lightThinkEnabled  bool
+	lightThinkInterval time.Duration
+
 	// 静默检测超时：用户多久不说话后昔涟可以主动搭话
 	// 默认 120 秒（2 分钟），设为 0 则禁用静默检测
 	silenceTimeout time.Duration
@@ -318,6 +322,9 @@ type ThinkerConfig struct {
 	OfflineThinkGap  time.Duration // 两次思考最小间隔 (离线，默认 10 分钟)
 
 	// 平台静默观察
+	LightThinkEnabled  bool
+	LightThinkInterval time.Duration // 轻量思考间隔 (默认 60s，0 = 禁用)
+
 	PlatformSilentThinkInterval time.Duration // 平台记忆观察间隔 (默认 600s，0 = 禁用)
 	PlatformChannels            []PlatformChannel
 }
@@ -339,6 +346,8 @@ func DefaultThinkerConfig() ThinkerConfig {
 		PostChatDelay:   getEnvDuration("THINK_POST_CHAT_DELAY_SEC", 5),
 		MinThinkGap:     getEnvDuration("THINK_MIN_GAP_SEC", 30),
 		OfflineThinkGap: getEnvDuration("THINK_OFFLINE_GAP_SEC", 600),
+		LightThinkEnabled:  getEnvBool("LIGHT_THINK_ENABLED", true),
+		LightThinkInterval: getEnvDuration("LIGHT_THINK_INTERVAL_SEC", 60),
 		PlatformSilentThinkInterval: getEnvDuration("PLATFORM_THINK_INTERVAL_SEC", 600),
 		PlatformChannels:            ParsePlatformChannels(os.Getenv("PLATFORM_CHANNELS")),
 	}
@@ -379,6 +388,8 @@ func NewThinker(
 		toolAdapter:         toolAdapter,
 		iotClient:           iotClient,
 		thinkInterval:       cfg.ThinkInterval,
+		lightThinkEnabled:   cfg.LightThinkEnabled,
+		lightThinkInterval:  cfg.LightThinkInterval,
 		silenceTimeout:      cfg.SilenceTimeout,
 		proactiveMsgMinGap:  getEnvDuration("PROACTIVE_MSG_MIN_GAP_SEC", 1800),
 		postChatDelay:       cfg.PostChatDelay,
@@ -426,6 +437,10 @@ func (t *Thinker) Start() {
 		t.wg.Add(1)
 		go t.periodicThinkLoop()
 	}
+	if t.lightThinkEnabled && t.lightThinkInterval > 0 {
+		t.wg.Add(1)
+		go t.lightThinkLoop()
+	}
 
 	// 启动平台静默观察循环
 	if len(t.platformChannels) > 0 && t.platformThinkInterval > 0 {
@@ -689,6 +704,93 @@ func (t *Thinker) performPlatformObservation() {
 	log.Printf("[后台思考] 平台观察摘要已生成 (长度=%d, 需要关注=%v)", len(result.Summary), result.NeedsAttention)
 }
 
+// lightThinkLoop runs frequent lightweight thinking cycles using a fast model.
+// It checks for urgent matters and can wake the deep thinker when needed.
+func (t *Thinker) lightThinkLoop() {
+	defer t.wg.Done()
+	defer func() {
+		if r := recover(); r != nil {
+			log.Printf("[后台思考] 轻量思考循环 panic 恢复: %v", r)
+		}
+	}()
+
+	log.Printf("[后台思考] 轻量思考已启动 (间隔=%v)", t.lightThinkInterval)
+
+	for {
+		select {
+		case <-t.stopCh:
+			log.Println("[后台思考] 轻量思考已停止")
+			return
+		case <-time.After(t.lightThinkInterval):
+			t.mu.Lock()
+			sinceLastUser := time.Since(t.lastUserMessage)
+			sinceLastThink := time.Since(t.lastThinkTime)
+			t.mu.Unlock()
+
+			// Skip if user was active recently (last 30s).
+			if sinceLastUser < 30*time.Second {
+				continue
+			}
+			// Skip if deep think just ran.
+			if sinceLastThink < 10*time.Second {
+				continue
+			}
+
+			t.performLightThink()
+		}
+	}
+}
+
+// performLightThink runs a single lightweight thinking cycle using the fast model.
+func (t *Thinker) performLightThink() {
+	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
+	defer cancel()
+
+	// Build a minimal system prompt.
+	now := time.Now()
+	systemPrompt := fmt.Sprintf(`你是昔涟。这是一次快速的内心检查（%s）。
+
+请用一句话在心里判断：
+1. 开拓者有什么需要立即关注的事情吗？（提醒、设备状态、情绪变化）
+2. 如果有紧急事项，输出【需要深思】标记；如果一切正常，输出一个字的感受即可。
+
+注意：只需要极简判断，不要长篇反思。`, now.Format("15:04"))
+
+	userPrompt := "快速检查一下。"
+	messages := []model.LLMMessage{
+		{Role: model.RoleSystem, Content: systemPrompt},
+		{Role: model.RoleUser, Content: userPrompt},
+	}
+
+	// Use fast model (toolAdapter) for light think.
+	resp, err := t.toolAdapter.Chat(ctx, messages)
+	if err != nil {
+		log.Printf("[轻量思考] LLM调用失败: %v", err)
+		return
+	}
+
+	content := resp.Content
+	if content == "" {
+		return
+	}
+
+	log.Printf("[轻量思考] %s", strings.TrimSpace(content))
+
+	// Check if deep think should be woken.
+	if strings.Contains(content, "【需要深思】") {
+		log.Println("[轻量思考] 检测到【需要深思】，唤醒深度思考...")
+		t.mu.Lock()
+		canDeep := time.Since(t.lastThinkTime) >= t.minThinkGap
+		t.mu.Unlock()
+		if canDeep {
+			t.performThink("light_wake")
+		} else {
+			log.Println("[轻量思考] 距上次深度思考太近，跳过唤醒")
+		}
+	}
+}
+
+// periodicThinkLoop 周期性自主思考循环
 // periodicThinkLoop 周期性自主思考循环
 //
 // 使用动态间隔：若配置了 ScheduleLoader，每次循环根据当前时段计算间隔；