diff --git a/task/task.go b/task/task.go
index 282eb47d..9233cff5 100644
--- a/task/task.go
+++ b/task/task.go
@@ -487,14 +487,12 @@ func (m *taskManager) StartTask() {
 
 func (m *taskManager) run() {
 	now := time.Now().Local()
-	m.taskLock.Lock()
-	for _, t := range m.adminTaskList {
-		t.SetNext(nil, now)
-	}
-	m.taskLock.Unlock()
+	// first run the tasks, so set all tasks next run time.
+	m.setTasksStartTime(now)
 
 	for {
 		// we only use RLock here because NewMapSorter copy the reference, do not change any thing
+		// here, we sort all task and get first task running time (effective).
 		m.taskLock.RLock()
 		sortList := NewMapSorter(m.adminTaskList)
 		m.taskLock.RUnlock()
@@ -507,49 +505,68 @@ func (m *taskManager) run() {
 		} else {
 			effective = sortList.Vals[0].GetNext(context.Background())
 		}
+
 		select {
-		case now = <-time.After(effective.Sub(now)):
-			// Run every entry whose next time was this effective time.
-			for _, e := range sortList.Vals {
-				if e.GetNext(context.Background()) != effective {
-					break
-				}
-
-				// check if timeout is on, if yes passing the timeout context
-				ctx := context.Background()
-				if duration := e.GetTimeout(ctx); duration != 0 {
-					ctx, cancelFunc := context.WithTimeout(ctx, duration)
-					go func() {
-						defer cancelFunc()
-						e.Run(ctx)
-					}()
-				} else {
-					go e.Run(ctx)
-				}
-
-				e.SetPrev(context.Background(), e.GetNext(context.Background()))
-				e.SetNext(nil, effective)
-			}
+		case now = <-time.After(effective.Sub(now)): // wait for effective time
+			runNextTasks(sortList, effective)
 			continue
-		case <-m.changed:
+		case <-m.changed: // tasks have been changed, set all tasks run again now
 			now = time.Now().Local()
-			m.taskLock.Lock()
-			for _, t := range m.adminTaskList {
-				t.SetNext(nil, now)
-			}
-			m.taskLock.Unlock()
+			m.setTasksStartTime(now)
 			continue
-		case <-m.stop:
-			m.taskLock.Lock()
-			if m.started {
-				m.started = false
-			}
-			m.taskLock.Unlock()
+		case <-m.stop: // manager is stopped, and mark manager is stopped
+			m.markManagerStop()
 			return
 		}
 	}
 }
 
+// setTasksStartTime is set all tasks next running time
+func (m *taskManager) setTasksStartTime(now time.Time) {
+	m.taskLock.Lock()
+	for _, task := range m.adminTaskList {
+		task.SetNext(nil, now)
+	}
+	m.taskLock.Unlock()
+}
+
+// markManagerStop it sets manager to be stopped
+func (m *taskManager) markManagerStop() {
+	m.taskLock.Lock()
+	if m.started {
+		m.started = false
+	}
+	m.taskLock.Unlock()
+}
+
+// runNextTasks it runs next task which next run time is equal to effective
+func runNextTasks(sortList *MapSorter, effective time.Time) *MapSorter {
+	// Run every entry whose next time was this effective time.
+	var i = 0
+	for _, e := range sortList.Vals {
+		i++
+		if e.GetNext(context.Background()) != effective {
+			break
+		}
+
+		// check if timeout is on, if yes passing the timeout context
+		ctx := context.Background()
+		if duration := e.GetTimeout(ctx); duration != 0 {
+			go func(e Tasker) {
+				ctx, cancelFunc := context.WithTimeout(ctx, duration)
+				defer cancelFunc()
+				e.Run(ctx)
+			}(e)
+		} else {
+			go e.Run(ctx)
+		}
+
+		e.SetPrev(context.Background(), e.GetNext(context.Background()))
+		e.SetNext(nil, effective)
+	}
+	return sortList
+}
+
 // StopTask stop all tasks
 func (m *taskManager) StopTask() {
 	go func() {
diff --git a/task/task_test.go b/task/task_test.go
index d36c3994..1078aa01 100644
--- a/task/task_test.go
+++ b/task/task_test.go
@@ -95,15 +95,17 @@ func TestTimeout(t *testing.T) {
 	defer m.ClearTask()
 	wg := &sync.WaitGroup{}
 	wg.Add(2)
+	once1, once2 := sync.Once{}, sync.Once{}
 
 	tk1 := NewTask("tk1", "0/10 * * ? * *",
 		func(ctx context.Context) error {
-			fmt.Println("tk1 start")
 			time.Sleep(4 * time.Second)
 			select {
 			case <-ctx.Done():
-				fmt.Println("tk1 done")
-				wg.Done()
+				once1.Do(func() {
+					fmt.Println("tk1 done")
+					wg.Done()
+				})
 				return errors.New("timeout")
 			default:
 			}
@@ -111,16 +113,17 @@ func TestTimeout(t *testing.T) {
 		}, TimeoutOption(3*time.Second),
 	)
 
-	tk2 := NewTask("tk2", "0/10 * * ? * *",
+	tk2 := NewTask("tk2", "0/11 * * ? * *",
 		func(ctx context.Context) error {
-			fmt.Println("tk2 start")
 			time.Sleep(4 * time.Second)
 			select {
 			case <-ctx.Done():
 				return errors.New("timeout")
 			default:
-				fmt.Println("tk2 done")
-				wg.Done()
+				once2.Do(func() {
+					fmt.Println("tk2 done")
+					wg.Done()
+				})
 			}
 			return nil
 		},