diff --git a/internal/datanode/data_node_test.go b/internal/datanode/data_node_test.go
index 7bd7bada42..377a849ae5 100644
--- a/internal/datanode/data_node_test.go
+++ b/internal/datanode/data_node_test.go
@@ -143,6 +143,8 @@ func TestDataNode(t *testing.T) {
 		err = node1.Start()
 		assert.Nil(t, err)
 		defer func() {
+			// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+			time.Sleep(200 * time.Millisecond)
 			err := node1.Stop()
 			assert.Nil(t, err)
 		}()
@@ -336,6 +338,8 @@ func TestDataNode(t *testing.T) {
 			if i <= 2 {
 				err = node.flowgraphManager.addAndStart(node, &datapb.VchannelInfo{CollectionID: 1, ChannelName: test.dmChannelName})
 				assert.Nil(t, err)
+				// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+				time.Sleep(200 * time.Millisecond)
 				vchanNameCh <- test.dmChannelName
 			}
 		}
@@ -409,6 +413,8 @@ func TestWatchChannel(t *testing.T) {
 		exist := node.flowgraphManager.exist(ch)
 		assert.True(t, exist)
 
+		// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+		time.Sleep(200 * time.Millisecond)
 		err = kv.RemoveWithPrefix(fmt.Sprintf("%s/%d", Params.DataNodeCfg.ChannelWatchSubPath, node.NodeID))
 		assert.Nil(t, err)
 		//TODO there is not way to sync Release done, use sleep for now
diff --git a/internal/datanode/flow_graph_manager_test.go b/internal/datanode/flow_graph_manager_test.go
index fd658ee737..5566b0bac6 100644
--- a/internal/datanode/flow_graph_manager_test.go
+++ b/internal/datanode/flow_graph_manager_test.go
@@ -19,6 +19,7 @@ package datanode
 import (
 	"context"
 	"testing"
+	"time"
 
 	"github.com/milvus-io/milvus/internal/proto/datapb"
 	"github.com/milvus-io/milvus/internal/proto/internalpb"
@@ -44,7 +45,11 @@ func TestFlowGraphManager(t *testing.T) {
 	require.Nil(t, err)
 
 	fm := newFlowgraphManager()
-	defer fm.dropAll()
+	defer func() {
+		// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+		time.Sleep(200 * time.Millisecond)
+		fm.dropAll()
+	}()
 	t.Run("Test addAndStart", func(t *testing.T) {
 		vchanName := "by-dev-rootcoord-dml-test-flowgraphmanager-addAndStart"
 		vchan := &datapb.VchannelInfo{
@@ -57,6 +62,8 @@ func TestFlowGraphManager(t *testing.T) {
 		assert.NoError(t, err)
 		assert.True(t, fm.exist(vchanName))
 
+		// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+		time.Sleep(200 * time.Millisecond)
 		fm.dropAll()
 	})
 
@@ -72,6 +79,8 @@ func TestFlowGraphManager(t *testing.T) {
 		assert.NoError(t, err)
 		assert.True(t, fm.exist(vchanName))
 
+		// TODO: wait for reconnecting to Pulsar, delete sleep after Seek wouldn't lead to disconnect with Pulsar
+		time.Sleep(200 * time.Millisecond)
 		fm.release(vchanName)
 
 		assert.False(t, fm.exist(vchanName))
diff --git a/internal/util/mqclient/pulsar_consumer.go b/internal/util/mqclient/pulsar_consumer.go
index 318d68f57c..c7a2dd995c 100644
--- a/internal/util/mqclient/pulsar_consumer.go
+++ b/internal/util/mqclient/pulsar_consumer.go
@@ -34,6 +34,7 @@ type PulsarConsumer struct {
 	closeCh    chan struct{}
 	once       sync.Once
 	skip       bool
+	closeOnce  sync.Once
 }
 
 // Subscription get a subscription for the consumer
@@ -104,8 +105,15 @@ func (pc *PulsarConsumer) Ack(message Message) {
 
 // Close the consumer and stop the broker to push more messages
 func (pc *PulsarConsumer) Close() {
-	pc.c.Close()
-	close(pc.closeCh)
+	pc.closeOnce.Do(func() {
+		defer pc.c.Close()
+		// Unsubscribe for the consumer
+		err := pc.c.Unsubscribe()
+		if err != nil {
+			panic(err)
+		}
+		close(pc.closeCh)
+	})
 }
 
 // patchEarliestMessageID unsafe patch logic to change messageID partitionIdx to 0
diff --git a/internal/util/mqclient/pulsar_consumer_test.go b/internal/util/mqclient/pulsar_consumer_test.go
index e408c5aad6..d9739a71d0 100644
--- a/internal/util/mqclient/pulsar_consumer_test.go
+++ b/internal/util/mqclient/pulsar_consumer_test.go
@@ -55,3 +55,29 @@ func Test_PatchEarliestMessageID(t *testing.T) {
 
 	assert.Equal(t, "-1:-1:0", fmt.Sprintf("%v", mid))
 }
+
+func TestPulsarConsumer_Close(t *testing.T) {
+	pulsarAddress, _ := Params.Load("_PulsarAddress")
+	pc, err := GetPulsarClientInstance(pulsar.ClientOptions{URL: pulsarAddress})
+	assert.Nil(t, err)
+
+	receiveChannel := make(chan pulsar.ConsumerMessage, 100)
+	consumer, err := pc.client.Subscribe(pulsar.ConsumerOptions{
+		Topic:                       "Topic-1",
+		SubscriptionName:            "SubName-1",
+		Type:                        pulsar.SubscriptionType(Exclusive),
+		SubscriptionInitialPosition: pulsar.SubscriptionInitialPosition(SubscriptionPositionEarliest),
+		MessageChannel:              receiveChannel,
+	})
+	assert.Nil(t, err)
+	assert.NotNil(t, consumer)
+
+	str := consumer.Subscription()
+	assert.NotNil(t, str)
+
+	pulsarConsumer := &PulsarConsumer{c: consumer, closeCh: make(chan struct{})}
+	pulsarConsumer.Close()
+
+	// test double close
+	pulsarConsumer.Close()
+}