diff --git a/make/migrations/postgresql/0004_add_robot_account.up.sql b/make/migrations/postgresql/0004_add_robot_account.up.sql
index 4c2579a3d..200268bae 100644
--- a/make/migrations/postgresql/0004_add_robot_account.up.sql
+++ b/make/migrations/postgresql/0004_add_robot_account.up.sql
@@ -3,7 +3,7 @@ CREATE TABLE robot (
  name varchar(255),
  description varchar(1024),
  project_id int,
- expiration int,
+ expiration bigint,
  disabled boolean DEFAULT false NOT NULL,
  creation_time timestamp default CURRENT_TIMESTAMP,
  update_time timestamp default CURRENT_TIMESTAMP,
diff --git a/src/common/config/metadata/metadatalist.go b/src/common/config/metadata/metadatalist.go
index 7e253f50d..f2034d4bf 100644
--- a/src/common/config/metadata/metadatalist.go
+++ b/src/common/config/metadata/metadatalist.go
@@ -130,6 +130,7 @@ var (
 		{Name: "with_chartmuseum", Scope: SystemScope, Group: BasicGroup, EnvKey: "WITH_CHARTMUSEUM", DefaultValue: "false", ItemType: &BoolType{}, Editable: true},
 		{Name: "with_clair", Scope: SystemScope, Group: BasicGroup, EnvKey: "WITH_CLAIR", DefaultValue: "false", ItemType: &BoolType{}, Editable: true},
 		{Name: "with_notary", Scope: SystemScope, Group: BasicGroup, EnvKey: "WITH_NOTARY", DefaultValue: "false", ItemType: &BoolType{}, Editable: true},
-		{Name: "robot_token_expiration", Scope: UserScope, Group: BasicGroup, EnvKey: "ROBOT_TOKEN_EXPIRATION", DefaultValue: "30", ItemType: &IntType{}, Editable: true},
+		// the unit of expiration is minute, 43200 minutes = 30 days
+		{Name: "robot_token_expiration", Scope: UserScope, Group: BasicGroup, EnvKey: "ROBOT_TOKEN_EXPIRATION", DefaultValue: "43200", ItemType: &IntType{}, Editable: true},
 	}
 )
diff --git a/src/core/api/robot.go b/src/core/api/robot.go
index 2cf5f28e0..066c928be 100644
--- a/src/core/api/robot.go
+++ b/src/core/api/robot.go
@@ -106,8 +106,8 @@ func (r *RobotAPI) Post() {
 	}
 
 	var robotReq models.RobotReq
-	// Expiration in days
-	tokenExpiration := time.Duration(config.RobotTokenExpiration()) * 24 * time.Hour
+	// Expiration in minutes
+	tokenExpiration := time.Duration(config.RobotTokenExpiration()) * time.Minute
 	expiresAt := time.Now().UTC().Add(tokenExpiration).Unix()
 	r.DecodeJSONReq(&robotReq)
 	createdName := common.RobotPrefix + robotReq.Name
diff --git a/src/core/config/config.go b/src/core/config/config.go
index e693d06c1..9966f7cc9 100644
--- a/src/core/config/config.go
+++ b/src/core/config/config.go
@@ -225,7 +225,7 @@ func TokenExpiration() (int, error) {
 	return cfgMgr.Get(common.TokenExpiration).GetInt(), nil
 }
 
-// RobotTokenExpiration returns the token expiration time of robot account (in day)
+// RobotTokenExpiration returns the token expiration time of robot account (in minute)
 func RobotTokenExpiration() int {
 	return cfgMgr.Get(common.RobotTokenExpiration).GetInt()
 }