diff --git a/builder/ucloud/uhost/consts.go b/builder/ucloud/uhost/consts.go
index b2a99ff65..c95ef1735 100644
--- a/builder/ucloud/uhost/consts.go
+++ b/builder/ucloud/uhost/consts.go
@@ -7,6 +7,16 @@ const (
 	defaultPasswordSpe = "-_"
 )
 
+const (
+	osTypeWindows             = "Windows"
+	securityGroupNonWeb       = "recommend non web"
+	instanceStateRunning      = "Running"
+	instanceStateStopped      = "Stopped"
+	bootDiskStateInitializing = "Initializing"
+	bootDiskStateNormal       = "Normal"
+	imageStateAvailable       = "Available"
+)
+
 var bootDiskTypeMap = map[string]string{
 	"cloud_ssd":    "CLOUD_SSD",
 	"local_normal": "LOCAL_NORMAL",
diff --git a/builder/ucloud/uhost/step_check_source_image.go b/builder/ucloud/uhost/step_check_source_image.go
index e0774f9c3..a8302a870 100644
--- a/builder/ucloud/uhost/step_check_source_image.go
+++ b/builder/ucloud/uhost/step_check_source_image.go
@@ -24,8 +24,8 @@ func (s *stepCheckSourceImageId) Run(ctx context.Context, state multistep.StateB
 		return halt(state, err, "Error on querying source_image_id")
 	}
 
-	if imageSet.OsType == "Windows" {
-		return halt(state, err, "The builder of ucloud-uhost not support make Windows image yet")
+	if imageSet.OsType == osTypeWindows {
+		return halt(state, err, "The builder of ucloud-uhost not support build Windows image yet")
 	}
 
 	state.Put("source_image", imageSet)
diff --git a/builder/ucloud/uhost/step_config_security_group.go b/builder/ucloud/uhost/step_config_security_group.go
index 533ce4904..713d4be11 100644
--- a/builder/ucloud/uhost/step_config_security_group.go
+++ b/builder/ucloud/uhost/step_config_security_group.go
@@ -52,7 +52,7 @@ func (s *stepConfigSecurityGroup) Run(ctx context.Context, state multistep.State
 		}
 
 		for _, item := range resp.DataSet {
-			if item.Type == "recommend non web" {
+			if item.Type == securityGroupNonWeb {
 				securityGroupId = item.FWId
 				break
 			}
diff --git a/builder/ucloud/uhost/step_copy_image.go b/builder/ucloud/uhost/step_copy_image.go
index fac0c517b..7bd818c3d 100644
--- a/builder/ucloud/uhost/step_copy_image.go
+++ b/builder/ucloud/uhost/step_copy_image.go
@@ -70,7 +70,7 @@ func (s *stepCopyUCloudImage) Run(ctx context.Context, state multistep.StateBag)
 				return err
 			}
 
-			if imageSet.State == "Available" {
+			if imageSet.State == imageStateAvailable {
 				expectedImages.Remove(v.Id())
 				continue
 			}
diff --git a/builder/ucloud/uhost/step_create_image.go b/builder/ucloud/uhost/step_create_image.go
index 1845ba50c..48268af2f 100644
--- a/builder/ucloud/uhost/step_create_image.go
+++ b/builder/ucloud/uhost/step_create_image.go
@@ -46,7 +46,7 @@ func (s *stepCreateImage) Run(ctx context.Context, state multistep.StateBag) mul
 		if err != nil {
 			return err
 		}
-		if inst == nil || inst.State != "Available" {
+		if inst == nil || inst.State != imageStateAvailable {
 			return newExpectedStateError("image", resp.ImageId)
 		}
 
diff --git a/builder/ucloud/uhost/step_create_instance.go b/builder/ucloud/uhost/step_create_instance.go
index 3ad1f75d2..e797d5fea 100644
--- a/builder/ucloud/uhost/step_create_instance.go
+++ b/builder/ucloud/uhost/step_create_instance.go
@@ -53,7 +53,7 @@ func (s *stepCreateInstance) Run(ctx context.Context, state multistep.StateBag)
 		if err != nil {
 			return err
 		}
-		if inst == nil || inst.State != "Running" {
+		if inst == nil || inst.State != instanceStateRunning {
 			return newExpectedStateError("instance", instanceId)
 		}
 
@@ -73,7 +73,7 @@ func (s *stepCreateInstance) Run(ctx context.Context, state multistep.StateBag)
 	s.instanceId = instanceId
 	state.Put("instance", instance)
 
-	if instance.BootDiskState == "Initializing" {
+	if instance.BootDiskState == bootDiskStateInitializing {
 		ui.Say(fmt.Sprintf("Waiting for boot disk of instance initialized when boot_disk_type is %q", s.BootDiskType))
 
 		err = retry.Config{
@@ -87,7 +87,7 @@ func (s *stepCreateInstance) Run(ctx context.Context, state multistep.StateBag)
 			if err != nil {
 				return err
 			}
-			if inst.BootDiskState != "Normal" {
+			if inst.BootDiskState != bootDiskStateNormal {
 				return newExpectedStateError("boot_disk of instance", instanceId)
 			}
 
@@ -136,7 +136,7 @@ func (s *stepCreateInstance) Cleanup(state multistep.StateBag) {
 		return
 	}
 
-	if instance.State != "Stopped" {
+	if instance.State != instanceStateStopped {
 		err = retry.Config{
 			Tries: 5,
 			ShouldRetry: func(err error) bool {
@@ -168,7 +168,7 @@ func (s *stepCreateInstance) Cleanup(state multistep.StateBag) {
 				return err
 			}
 
-			if instance.State != "Stopped" {
+			if instance.State != instanceStateStopped {
 				return newExpectedStateError("instance", s.instanceId)
 			}
 
diff --git a/builder/ucloud/uhost/step_stop_instance.go b/builder/ucloud/uhost/step_stop_instance.go
index ebc645da5..621633b3c 100644
--- a/builder/ucloud/uhost/step_stop_instance.go
+++ b/builder/ucloud/uhost/step_stop_instance.go
@@ -26,7 +26,7 @@ func (s *stepStopInstance) Run(ctx context.Context, state multistep.StateBag) mu
 		return halt(state, err, fmt.Sprintf("Error on reading instance when stop %q", instance.UHostId))
 	}
 
-	if instance.State != "Stopped" {
+	if instance.State != instanceStateStopped {
 		stopReq := conn.NewPoweroffUHostInstanceRequest()
 		stopReq.UHostId = ucloud.String(instance.UHostId)
 		ui.Say(fmt.Sprintf("Stopping instance %q", instance.UHostId))
@@ -59,7 +59,7 @@ func (s *stepStopInstance) Run(ctx context.Context, state multistep.StateBag) mu
 				return err
 			}
 
-			if instance.State != "Stopped" {
+			if instance.State != instanceStateStopped {
 				return newExpectedStateError("instance", instance.UHostId)
 			}
 
diff --git a/builder/ucloud/uhost/utils.go b/builder/ucloud/uhost/utils.go
index 1d2ed14b4..55f43a510 100644
--- a/builder/ucloud/uhost/utils.go
+++ b/builder/ucloud/uhost/utils.go
@@ -8,28 +8,28 @@ import (
 	"strings"
 )
 
-func checkStringIn(val string, availables []string) error {
-	for _, choice := range availables {
+func checkStringIn(val string, available []string) error {
+	for _, choice := range available {
 		if val == choice {
 			return nil
 		}
 	}
 
-	return fmt.Errorf("should be one of %q, got %q", strings.Join(availables, ","), val)
+	return fmt.Errorf("should be one of %q, got %q", strings.Join(available, ","), val)
 }
 
-func checkIntIn(val int, availables []int) error {
-	for _, choice := range availables {
+func checkIntIn(val int, available []int) error {
+	for _, choice := range available {
 		if val == choice {
 			return nil
 		}
 	}
 
-	return fmt.Errorf("should be one of %v, got %d", availables, val)
+	return fmt.Errorf("should be one of %v, got %d", available, val)
 }
 
-func isStringIn(val string, availables []string) bool {
-	for _, choice := range availables {
+func isStringIn(val string, available []string) bool {
+	for _, choice := range available {
 		if val == choice {
 			return true
 		}