diff --git a/coupon/helper.go b/coupon/helper.go
index 768fe7b..1eeab02 100644
--- a/coupon/helper.go
+++ b/coupon/helper.go
@@ -1,6 +1,7 @@
 package coupon
 
 import (
+	"crypto/md5"
 	"encoding/binary"
 	"encoding/hex"
 	"math/rand"
@@ -41,8 +42,12 @@ func DisolveCouponCode(code string) (round string, key string) {
 }
 
 func MakeCouponRoundHash(name string) (hash string, roundNumber uint32) {
+	m5 := md5.New()
+	m5.Write([]byte(name))
+	hashbt := m5.Sum(nil)
+
 	roundbt := make([]byte, 8)
-	copy(roundbt, []byte(strings.ToLower(name)))
+	copy(roundbt, hashbt[:8])
 
 	roundseed := int64(binary.BigEndian.Uint64(roundbt))
 	roundhash := make([]byte, 4)