diff --git a/code/rest/preference_controller.go b/code/rest/preference_controller.go
index e3cd9d1..6f63a35 100644
--- a/code/rest/preference_controller.go
+++ b/code/rest/preference_controller.go
@@ -2,10 +2,10 @@ package rest
 
 import (
 	"github.com/eyebluecn/tank/code/core"
+	"github.com/eyebluecn/tank/code/tool/i18n"
 	"github.com/eyebluecn/tank/code/tool/result"
 	"github.com/eyebluecn/tank/code/tool/util"
 	jsoniter "github.com/json-iterator/go"
-	"github.com/robfig/cron/v3"
 	"net/http"
 	"strconv"
 )
@@ -152,6 +152,9 @@ func (this *PreferenceController) EditPreviewConfig(writer http.ResponseWriter,
 func (this *PreferenceController) EditScanConfig(writer http.ResponseWriter, request *http.Request) *result.WebResult {
 
 	scanConfigStr := request.FormValue("scanConfig")
+	if scanConfigStr == "" {
+		panic(result.BadRequest("scanConfig cannot be null"))
+	}
 
 	preference := this.preferenceDao.Fetch()
 
@@ -164,8 +167,9 @@ func (this *PreferenceController) EditScanConfig(writer http.ResponseWriter, req
 	//validate the scan config.
 	if scanConfig.Enable {
 		//validate cron.
-		_, err := cron.ParseStandard(scanConfig.Cron)
-		this.PanicError(err)
+		if !util.ValidateCron(scanConfig.Cron) {
+			panic(result.CustomWebResultI18n(request, result.SHARE_CODE_ERROR, i18n.CronValidateError))
+		}
 
 		//validate scope.
 		if scanConfig.Scope == SCAN_SCOPE_CUSTOM {
@@ -179,6 +183,7 @@ func (this *PreferenceController) EditScanConfig(writer http.ResponseWriter, req
 		}
 	}
 
+	preference.ScanConfig = scanConfigStr
 	preference = this.preferenceService.Save(preference)
 
 	//reinit the scan task.
diff --git a/code/tool/i18n/i18n.go b/code/tool/i18n/i18n.go
index ae9ac26..5fd9666 100644
--- a/code/tool/i18n/i18n.go
+++ b/code/tool/i18n/i18n.go
@@ -45,6 +45,7 @@ var (
 	ShareNumExceedLimit            = &Item{English: `sharing files' num exceed the limit %d > %d`, Chinese: `一次分享的文件数量超出限制了 %d > %d `}
 	ShareCodeRequired              = &Item{English: `share code required`, Chinese: `提取码必填`}
 	ShareCodeError                 = &Item{English: `share code error`, Chinese: `提取码错误`}
+	CronValidateError              = &Item{English: `cron error. five fields needed. eg: 1 * * * *`, Chinese: `Cron表达式错误，必须为5位。例如：1 * * * *`}
 )
 
 func (this *Item) Message(request *http.Request) string {