diff --git a/server/controllers/down.go b/server/controllers/down.go
index 2797ad46..1a46183d 100644
--- a/server/controllers/down.go
+++ b/server/controllers/down.go
@@ -7,7 +7,6 @@ import (
 	"github.com/Xhofe/alist/utils"
 	"github.com/gin-gonic/gin"
 	log "github.com/sirupsen/logrus"
-	"path"
 )
 
 func Down(c *gin.Context) {
@@ -19,7 +18,7 @@ func Down(c *gin.Context) {
 		common.ErrorResp(c, err, 500)
 		return
 	}
-	if driver.Config().OnlyProxy || account.Proxy || utils.IsContain(conf.DProxyTypes, path.Ext(rawPath)) {
+	if driver.Config().OnlyProxy || account.Proxy || utils.IsContain(conf.DProxyTypes, utils.Ext(rawPath)) {
 		Proxy(c)
 		return
 	}
diff --git a/server/controllers/proxy.go b/server/controllers/proxy.go
index 8209715f..8c47727a 100644
--- a/server/controllers/proxy.go
+++ b/server/controllers/proxy.go
@@ -30,7 +30,7 @@ func Proxy(c *gin.Context) {
 	// 4. 开启webdav中转（需要验证sign）
 	if !account.Proxy && !driver.Config().OnlyProxy &&
 		utils.GetFileType(filepath.Ext(rawPath)) != conf.TEXT &&
-		!utils.IsContain(conf.DProxyTypes, filepath.Ext(rawPath)) {
+		!utils.IsContain(conf.DProxyTypes, utils.Ext(rawPath)) {
 		// 只开启了webdav中转，验证sign
 		ok := false
 		if account.WebdavProxy {
diff --git a/utils/file.go b/utils/file.go
index ce30e3b4..2c462969 100644
--- a/utils/file.go
+++ b/utils/file.go
@@ -35,7 +35,7 @@ func GetFileType(ext string) int {
 	if ext == "" {
 		return conf.UNKNOWN
 	}
-	ext = strings.ToLower(strings.TrimLeft(ext, "."))
+	ext = strings.ToLower(strings.TrimPrefix(ext, "."))
 	if IsContain(conf.OfficeTypes, ext) {
 		return conf.OFFICE
 	}
@@ -128,10 +128,6 @@ func Split(p string) (string, string) {
 	return path.Split(p)
 }
 
-// FormatName TODO
-func FormatName(name string) string {
-	name = strings.ReplaceAll(name, "/", " ")
-	name = strings.ReplaceAll(name, "#", " ")
-	name = strings.ReplaceAll(name, "?", " ")
-	return name
+func Ext(name string) string {
+	return strings.TrimPrefix(path.Ext(name), ".")
 }
diff --git a/utils/md5.go b/utils/md5.go
index 2cd85e63..92f9ebc2 100644
--- a/utils/md5.go
+++ b/utils/md5.go
@@ -13,14 +13,12 @@ func GetSHA1Encode(data string) string {
 	return hex.EncodeToString(h.Sum(nil))
 }
 
-// GetMD5Encode
 func GetMD5Encode(data string) string {
 	h := md5.New()
 	h.Write([]byte(data))
 	return hex.EncodeToString(h.Sum(nil))
 }
 
-// Get16MD5Encode
 func Get16MD5Encode(data string) string {
 	return GetMD5Encode(data)[8:24]
 }