diff --git a/util/string.go b/util/string.go
index a4fde46..0ce9684 100644
--- a/util/string.go
+++ b/util/string.go
@@ -24,8 +24,8 @@ func GenRandomString(source string, length uint) string {
 		return ""
 	}
 	if len(source) == 0 {
-		//字符串为空，默认字符源为如下:
-		source = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+		//字符串为空，默认字符源为如下(去除易混淆的i/l):
+		source = "0123456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNOPQRSTUVWXYZ"
 	}
 	strByte := []byte(source)
 	var genStrByte = make([]byte, 0)