diff --git a/pkg/hostman/guestman/guesttasks.go b/pkg/hostman/guestman/guesttasks.go
index 3b1cc602d6..534dc99b8a 100644
--- a/pkg/hostman/guestman/guesttasks.go
+++ b/pkg/hostman/guestman/guesttasks.go
@@ -342,6 +342,8 @@ type SGuestNetworkSyncTask struct {
 	addNics []jsonutils.JSONObject
 	errors  []error
 
+	changedNics [][]jsonutils.JSONObject
+
 	callback func(...error)
 }
 
@@ -360,10 +362,39 @@ func (n *SGuestNetworkSyncTask) syncNetworkConf() {
 		n.addNics = n.addNics[:len(n.addNics)-1]
 		n.addNic(nic)
 	} else {
+		if len(n.changedNics) > 0 {
+			for i := range n.changedNics {
+				n.onNicChange(n.changedNics[i][0], n.changedNics[i][1])
+			}
+		}
 		n.callback(n.errors...)
 	}
 }
 
+func (n *SGuestNetworkSyncTask) onNicChange(oldNic, newNic jsonutils.JSONObject) {
+	oldbr, _ := oldNic.GetString("bridge")
+	oldifname, _ := oldNic.GetString("ifname")
+	newbr, _ := newNic.GetString("bridge")
+	newifname, _ := newNic.GetString("ifname")
+	if oldbr != newbr {
+		// bridge changed
+		if oldifname == newifname {
+			output, err := procutils.NewRemoteCommandAsFarAsPossible("ovs-vsctl", "del-port", oldbr, oldifname).Output()
+			log.Debugf("ovs-vsctl del-port %s %s: %s", oldbr, oldifname, output)
+			if err != nil {
+				n.errors = append(n.errors, err)
+			}
+			output, err = procutils.NewRemoteCommandAsFarAsPossible("ovs-vsctl", "add-port", newbr, newifname).Output()
+			log.Debugf("ovs-vsctl add-port %s %s: %s", newbr, newifname, output)
+			if err != nil {
+				n.errors = append(n.errors, err)
+			}
+		} else {
+			log.Errorf("cannot change both bridge(%s!=%s) and ifname(%s!=%s)!!!!!", oldbr, newbr, oldifname, newifname)
+		}
+	}
+}
+
 func (n *SGuestNetworkSyncTask) removeNic(nic jsonutils.JSONObject) {
 	ifname, _ := nic.GetString("ifname")
 	callback := func(res string) {
@@ -460,8 +491,8 @@ func (n *SGuestNetworkSyncTask) onDeviceAdd(nic jsonutils.JSONObject) {
 	n.syncNetworkConf()
 }
 
-func NewGuestNetworkSyncTask(guest *SKVMGuestInstance, delNics, addNics []jsonutils.JSONObject) *SGuestNetworkSyncTask {
-	return &SGuestNetworkSyncTask{guest, delNics, addNics, make([]error, 0), nil}
+func NewGuestNetworkSyncTask(guest *SKVMGuestInstance, delNics, addNics []jsonutils.JSONObject, changedNics [][]jsonutils.JSONObject) *SGuestNetworkSyncTask {
+	return &SGuestNetworkSyncTask{guest, delNics, addNics, make([]error, 0), changedNics, nil}
 }
 
 /**
diff --git a/pkg/hostman/guestman/qemu-kvm.go b/pkg/hostman/guestman/qemu-kvm.go
index a7fa5b6ec4..bbfe0d28cb 100644
--- a/pkg/hostman/guestman/qemu-kvm.go
+++ b/pkg/hostman/guestman/qemu-kvm.go
@@ -1099,7 +1099,7 @@ func (s *SKVMGuestInstance) compareDescCdrom(newDesc jsonutils.JSONObject) *stri
 	}
 }
 
-func (s *SKVMGuestInstance) compareDescNetworks(newDesc jsonutils.JSONObject) ([]jsonutils.JSONObject, []jsonutils.JSONObject) {
+func (s *SKVMGuestInstance) compareDescNetworks(newDesc jsonutils.JSONObject) ([]jsonutils.JSONObject, []jsonutils.JSONObject, [][]jsonutils.JSONObject) {
 	var isValid = func(net jsonutils.JSONObject) bool {
 		driver, _ := net.GetString("driver")
 		return driver == "virtio"
@@ -1117,9 +1117,11 @@ func (s *SKVMGuestInstance) compareDescNetworks(newDesc jsonutils.JSONObject) ([
 	}
 
 	var delNics, addNics = []jsonutils.JSONObject{}, []jsonutils.JSONObject{}
+	var changedNics = [][]jsonutils.JSONObject{}
 	nics, _ := newDesc.GetArray("nics")
 	for _, n := range nics {
 		if isValid(n) {
+			// assume all nics in new desc are new
 			addNics = append(addNics, n)
 		}
 	}
@@ -1129,24 +1131,31 @@ func (s *SKVMGuestInstance) compareDescNetworks(newDesc jsonutils.JSONObject) ([
 		if isValid(n) {
 			idx := findNet(addNics, n)
 			if idx >= 0 {
-				// remove n
+				// check if bridge changed
+				changedNics = append(changedNics, []jsonutils.JSONObject{
+					n,            // old
+					addNics[idx], // new
+				})
+				// remove existing nic from new
 				addNics = append(addNics[:idx], addNics[idx+1:]...)
 			} else {
+				// not found, remove the nic
 				delNics = append(delNics, n)
 			}
 		}
 	}
-	return delNics, addNics
+	return delNics, addNics, changedNics
 }
 
 func (s *SKVMGuestInstance) SyncConfig(ctx context.Context, desc jsonutils.JSONObject, fwOnly bool) (jsonutils.JSONObject, error) {
 	var delDisks, addDisks, delNetworks, addNetworks []jsonutils.JSONObject
+	var changedNetworks [][]jsonutils.JSONObject
 	var cdrom *string
 
 	if !fwOnly {
 		delDisks, addDisks = s.compareDescDisks(desc)
 		cdrom = s.compareDescCdrom(desc)
-		delNetworks, addNetworks = s.compareDescNetworks(desc)
+		delNetworks, addNetworks, changedNetworks = s.compareDescNetworks(desc)
 	}
 	if err := s.SaveDesc(desc); err != nil {
 		return nil, err
@@ -1190,7 +1199,7 @@ func (s *SKVMGuestInstance) SyncConfig(ctx context.Context, desc jsonutils.JSONO
 	}
 
 	if len(delNetworks)+len(addNetworks) > 0 {
-		task := NewGuestNetworkSyncTask(s, delNetworks, addNetworks)
+		task := NewGuestNetworkSyncTask(s, delNetworks, addNetworks, changedNetworks)
 		runTaskNames = append(runTaskNames, jsonutils.NewString("networksync"))
 		tasks = append(tasks, task)
 	}