diff --git a/conn.go b/conn.go
index d92dceb..17e87b2 100644
--- a/conn.go
+++ b/conn.go
@@ -541,9 +541,10 @@ func (c *Conn) writerDelayBufInner() (err error) {
 	return
 }
 
-// 延迟写消息
+// 延迟写消息, 对流量密集型的场景有用
 // 1. 如果缓存的消息超过了多少条数
 // 2. 如果缓存的消费超过了多久的时间
+// 3. TODO 最大缓存多少字节
 func (c *Conn) WriteMessageDelay(op Opcode, writeBuf []byte) (err error) {
 	if atomic.LoadInt32(&c.closed) == 1 {
 		return ErrClosed
diff --git a/conn_test.go b/conn_test.go
index 5a349fb..bcc04ad 100644
--- a/conn_test.go
+++ b/conn_test.go
@@ -35,19 +35,21 @@ var (
 
 type testMessageHandler struct {
 	DefCallback
-	t       *testing.T
-	need    []byte
-	callbed int32
-	server  bool
-	count   int
-	got     chan []byte
-	done    chan struct{}
-	output  bool
+	t           *testing.T
+	need        []byte
+	callbed     int32
+	callbedChan chan bool
+	server      bool
+	count       int
+	got         chan []byte
+	done        chan struct{}
+	output      bool
 }
 
 func (t *testMessageHandler) OnMessage(c *Conn, op opcode.Opcode, msg []byte) {
 	need := append([]byte(nil), t.need...)
 	atomic.StoreInt32(&t.callbed, 1)
+	t.callbedChan <- true
 	if t.count == 0 {
 		return
 	}
@@ -96,7 +98,7 @@ func (t *testMessageHandler) OnClose(c *Conn, err error) {
 func newServrEcho(t *testing.T, data []byte, output bool) *httptest.Server {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		c, err := Upgrade(w, r,
-			WithServerCallback(&testMessageHandler{t: t, need: data, server: true, count: -1, output: true}),
+			WithServerCallback(&testMessageHandler{t: t, need: data, server: true, count: -1, output: true, callbedChan: make(chan bool, 1)}),
 		)
 		if err != nil {
 			t.Error(err)
@@ -115,6 +117,7 @@ func Test_ReadMessage(t *testing.T) {
 	t.Run("ReadMessage10", func(t *testing.T) {
 		ts := newServrEcho(t, testBinaryMessage10, true)
 		client := &testMessageHandler{t: t, need: append([]byte(nil), testBinaryMessage10...), count: 1, done: make(chan struct{}), output: true}
+		client.callbedChan = make(chan bool, 1)
 		c, err := Dial(ts.URL, WithClientCallback(client))
 		if err != nil {
 			t.Error(err)
@@ -130,7 +133,10 @@ func Test_ReadMessage(t *testing.T) {
 			return
 		}
 		// <-client.done
-		time.Sleep(time.Second / 3)
+		select {
+		case <-client.callbedChan:
+		case <-time.After(time.Second / 3):
+		}
 		if atomic.LoadInt32(&client.callbed) != 1 {
 			t.Error("not callbed")
 		}
@@ -139,6 +145,7 @@ func Test_ReadMessage(t *testing.T) {
 	t.Run("ReadMessage64K", func(t *testing.T) {
 		ts := newServrEcho(t, testBinaryMessage64kb, false)
 		client := &testMessageHandler{t: t, need: append([]byte(nil), testBinaryMessage64kb...), count: 1}
+		client.callbedChan = make(chan bool, 1)
 		c, err := Dial(ts.URL, WithClientCallback(client))
 		if err != nil {
 			t.Error(err)
@@ -148,7 +155,10 @@ func Test_ReadMessage(t *testing.T) {
 
 		tmp := append([]byte(nil), testBinaryMessage64kb...)
 		err = c.WriteMessage(Binary, tmp)
-		time.Sleep(time.Second / 3)
+		select {
+		case <-client.callbedChan:
+		case <-time.After(time.Second / 3):
+		}
 		if err != nil {
 			t.Error(err)
 			return
@@ -162,6 +172,7 @@ func Test_ReadMessage(t *testing.T) {
 	t.Run("ReadMessage64K_Text", func(t *testing.T) {
 		ts := newServrEcho(t, testTextMessage64kb, false)
 		client := &testMessageHandler{t: t, need: append([]byte(nil), testTextMessage64kb...), count: 1}
+		client.callbedChan = make(chan bool, 1)
 		c, err := Dial(ts.URL, WithClientCallback(client))
 		if err != nil {
 			t.Error(err)
@@ -176,8 +187,10 @@ func Test_ReadMessage(t *testing.T) {
 			t.Error(err)
 			return
 		}
-		time.Sleep(time.Second / 3)
-
+		select {
+		case <-client.callbedChan:
+		case <-time.After(time.Second / 3):
+		}
 		if atomic.LoadInt32(&client.callbed) != 1 {
 			t.Errorf("not callbed:%d\n", client.callbed)
 		}