diff --git a/pkg/apis/scheduler/api.go b/pkg/apis/scheduler/api.go
index 83d0602a6b..9645e64569 100644
--- a/pkg/apis/scheduler/api.go
+++ b/pkg/apis/scheduler/api.go
@@ -86,6 +86,11 @@ type ScheduleInput struct {
 	// we don't need reallocate network
 	ReuseNetwork bool `json:"reuse_network"`
 
+	// Change config
+	ChangeConfig bool
+	// guest who change config has isolated device
+	HasIsolatedDevice bool
+
 	PendingUsages []jsonutils.JSONObject
 }
 
diff --git a/pkg/compute/models/guest_actions.go b/pkg/compute/models/guest_actions.go
index 085e7a7f61..a1bc16371c 100644
--- a/pkg/compute/models/guest_actions.go
+++ b/pkg/compute/models/guest_actions.go
@@ -2542,7 +2542,7 @@ func (self *SGuest) PerformChangeConfig(ctx context.Context, userCred mcclient.T
 	}
 
 	// schedulr forecast
-	schedDesc := self.confToSchedDesc(addCpu, addMem, addDisk)
+	schedDesc := self.changeConfToSchedDesc(addCpu, addMem, addDisk)
 	s := auth.GetAdminSession(ctx, options.Options.Region, "")
 	canChangeConf, err := modules.SchedManager.DoScheduleForecast(s, schedDesc, 1)
 	if err != nil {
@@ -2588,7 +2588,7 @@ func (self *SGuest) PerformChangeConfig(ctx context.Context, userCred mcclient.T
 	return nil, nil
 }
 
-func (self *SGuest) confToSchedDesc(addCpu, addMem, addDisk int) *schedapi.ScheduleInput {
+func (self *SGuest) changeConfToSchedDesc(addCpu, addMem, addDisk int) *schedapi.ScheduleInput {
 	guestDisks := self.GetDisks()
 	diskInfo := guestDisks[0].ToDiskConfig()
 	diskInfo.SizeMb = addDisk
@@ -2605,6 +2605,8 @@ func (self *SGuest) confToSchedDesc(addCpu, addMem, addDisk int) *schedapi.Sched
 			Project: self.ProjectId,
 			Domain:  self.DomainId,
 		},
+		ChangeConfig:      true,
+		HasIsolatedDevice: len(self.GetIsolatedDevices()) > 0,
 	}
 	return desc
 }
diff --git a/pkg/scheduler/algorithm/predicates/predicates.go b/pkg/scheduler/algorithm/predicates/predicates.go
index d14aeac4dd..4b8aa0dedd 100644
--- a/pkg/scheduler/algorithm/predicates/predicates.go
+++ b/pkg/scheduler/algorithm/predicates/predicates.go
@@ -200,7 +200,7 @@ func (h *PredicateHelper) UseReserved() bool {
 	usable := false
 	data := h.Unit.SchedData()
 	isoDevs := data.IsolatedDevices
-	if len(isoDevs) > 0 {
+	if len(isoDevs) > 0 || (data.ChangeConfig && data.HasIsolatedDevice) {
 		usable = true
 	}
 	return usable