diff --git a/internal/services/callback.go b/internal/services/callback.go
index 3a69526..f1a9447 100644
--- a/internal/services/callback.go
+++ b/internal/services/callback.go
@@ -34,9 +34,19 @@ func NewCallbackService(cfg *config.Config, gateway *gateway.Gateway, dingtalkCl
 
 // Envelope 回调统一请求体
 type Envelope struct {
-	Action string            `json:"action"`
-	TaskID string            `json:"task_id"`
-	Data   map[string]string `json:"data"`
+	Action string          `json:"action"`
+	TaskID string          `json:"task_id"`
+	Data   json.RawMessage `json:"data"`
+}
+
+// bug_optimization_submit_done 工单完成回调
+const ActionBugOptimizationSubmitDone = "bug_optimization_submit_done"
+
+// BugOptimizationSubmitDoneData 工单完成回调数据
+type BugOptimizationSubmitDoneData struct {
+	Receivers  []string `json:"receivers"`
+	DetailPage string   `json:"detail_page"`
+	Msg        string   `json:"msg"`
 }
 
 // Callback 统一回调处理
@@ -47,7 +57,7 @@ func (s *CallbackService) Callback(c *fiber.Ctx) error {
 	ts := strings.TrimSpace(c.Get("X-Timestamp"))
 
 	// 时间窗口（如果提供了 ts 则校验，否则跳过），窗口 5 分钟
-	if ts != "" && !validateTimestamp(ts, 300*time.Minute) {
+	if ts != "" && !validateTimestamp(ts, 5*time.Minute) {
 		return errorcode.AuthNotFound
 	}
 
@@ -59,7 +69,7 @@ func (s *CallbackService) Callback(c *fiber.Ctx) error {
 	if env.Action == "" || env.TaskID == "" {
 		return errorcode.ParamErr("missing action/task_id")
 	}
-	if len(env.Data) == 0 {
+	if env.Data == nil {
 		return errorcode.ParamErr("missing data")
 	}
 
@@ -109,35 +119,31 @@ func parseInt64(s string) (int64, bool) {
 func (s *CallbackService) handleDingTalkCallback(c *fiber.Ctx, env Envelope) error {
 	switch env.Action {
 	// bug/优化完成回调
-	case "bug_optimization_submit_done":
+	case ActionBugOptimizationSubmitDone:
 		// 获取 session_id
 		sessionID, ok := s.botTool.GetSessionByTaskID(env.TaskID)
 		if !ok {
 			return errorcode.ParamErr("missing session_id for task_id: %s", env.TaskID)
 		}
 
-		// 获取接收者
-		receiverJson := env.Data["receivers"]
-		if receiverJson == "" {
-			return errorcode.ParamErr("missing receivers")
+		var data BugOptimizationSubmitDoneData
+		if err := json.Unmarshal(env.Data, &data); err != nil {
+			return errorcode.ParamErr("invalid data type: %v", err)
 		}
-		var receiverIds []string
-		if err := json.Unmarshal([]byte(receiverJson), &receiverIds); err != nil {
-			return errorcode.ParamErr("invalid receivers: %v", err)
-		}
-		if len(receiverIds) == 0 {
+
+		if len(data.Receivers) == 0 {
 			return errorcode.ParamErr("empty receivers")
 		}
 		// 构建接收者
-		receivers := s.getDingtalkReceivers(c.Context(), receiverIds)
+		receivers := s.getDingtalkReceivers(c.Context(), data.Receivers)
 
 		// 构建跳转链接
-		detailPage := env.Data["detail_page"]
-		if detailPage != "" {
-			detailPage = util.BuildJumpLink(detailPage, "去查看")
+		var detailPage string
+		if data.DetailPage != "" {
+			detailPage = util.BuildJumpLink(data.DetailPage, "去查看")
 		}
 
-		msg := env.Data["msg"]
+		msg := data.Msg
 		msg = util.ReplacePlaceholder(msg, "receivers", receivers)
 		msg = util.ReplacePlaceholder(msg, "detail_page", detailPage)