diff --git a/cmd/update.go b/cmd/update.go
index ee27e07..4cedba5 100644
--- a/cmd/update.go
+++ b/cmd/update.go
@@ -2,21 +2,28 @@ package cmd
 
 import (
 	"github.com/zu1k/nali/internal/db"
+	"strings"
 
 	"github.com/spf13/cobra"
 )
 
 // updateCmd represents the update command
 var updateCmd = &cobra.Command{
-	Use:   "update",
-	Short: "update chunzhen ip database",
-	Long:  `update chunzhen ip database`,
+	Use:     "update",
+	Short:   "update chunzhen, zxipv6, ip2region ip database and cdn",
+	Long:    `update chunzhen, zxipv6, ip2region ip database and cdn. Use commas to separate`,
+	Example: "nali update --db chunzhen,cdn",
 	Run: func(cmd *cobra.Command, args []string) {
-		db.UpdateAllDB()
-
+		DBs, _ := cmd.Flags().GetString("db")
+		var DBNameArray []string
+		if DBs != "" {
+			DBNameArray = strings.Split(DBs, ",")
+		}
+		db.UpdateDB(DBNameArray...)
 	},
 }
 
 func init() {
 	rootCmd.AddCommand(updateCmd)
+	rootCmd.PersistentFlags().String("db", "", "choose db you want to update")
 }
diff --git a/internal/db/db.go b/internal/db/db.go
index 617e5ce..e890318 100644
--- a/internal/db/db.go
+++ b/internal/db/db.go
@@ -104,27 +104,62 @@ func GetIPDBbyName(name string) (dbif.DB, error) {
 	}
 }
 
-func UpdateAllDB() {
-	log.Println("正在下载最新 纯真 IPv4数据库...")
-	_, err := qqwry.Download(QQWryPath)
-	if err != nil {
-		log.Fatalln("数据库 QQWry 下载失败:", err)
+func getDBInfoMap() map[string]func() error {
+	return map[string]func() error{
+		"chunzhen": func() error {
+			log.Println("正在下载最新 纯真 IPv4数据库...")
+			_, err := qqwry.Download(QQWryPath)
+			if err != nil {
+				log.Fatalln("数据库 QQWry 下载失败:", err)
+			}
+			return err
+		},
+		"zxipv6": func() error {
+			log.Println("正在下载最新 ZX IPv6数据库...")
+			_, err := zxipv6wry.Download(ZXIPv6WryPath)
+			if err != nil {
+				log.Fatalln("数据库 ZXIPv6Wry 下载失败:", err)
+			}
+			return err
+		},
+		"ip2region": func() error {
+			log.Println("正在下载最新 Ip2Region 数据库...")
+			_, err := ip2region.Download(Ip2RegionPath)
+			if err != nil {
+				log.Fatalln("数据库 Ip2Region 下载失败:", err)
+			}
+			return err
+		},
+		"cdn": func() error {
+			log.Println("正在下载最新 CDN服务提供商数据库...")
+			_, err := cdn.Download(CDNPath)
+			if err != nil {
+				log.Fatalln("数据库 CDN 下载失败:", err)
+			}
+			return err
+		},
 	}
+}
 
-	log.Println("正在下载最新 ZX IPv6数据库...")
-	_, err = zxipv6wry.Download(ZXIPv6WryPath)
-	if err != nil {
-		log.Fatalln("数据库 ZXIPv6Wry 下载失败:", err)
+func UpdateDB(dbName ...string) {
+	dbInfo := getDBInfoMap()
+	isAll := false
+	if len(dbName) == 0 {
+		isAll = true
 	}
-	_, err = ip2region.Download(Ip2RegionPath)
-	if err != nil {
-		log.Fatalln("数据库 Ip2Region 下载失败:", err)
+	keySet := make(map[string]struct{})
+	for _, v := range dbName {
+		keySet[v] = struct{}{}
 	}
-
-	log.Println("正在下载最新 CDN服务提供商数据库...")
-	_, err = cdn.Download(CDNPath)
-	if err != nil {
-		log.Fatalln("数据库 CDN 下载失败:", err)
+	for key, action := range dbInfo {
+		_, ok := keySet[key]
+		if !isAll && !ok {
+			continue
+		}
+		if err := action(); err != nil {
+			// keep loop
+			continue
+		}
 	}
 }