diff --git a/backend/verifyCode/0 b/backend/verifyCode/0
new file mode 100644
index 0000000..e69de29
diff --git a/backend/verifyCode/cmd/verifyCode/main.go b/backend/verifyCode/cmd/verifyCode/main.go
index 4830be6..b3aa721 100644
--- a/backend/verifyCode/cmd/verifyCode/main.go
+++ b/backend/verifyCode/cmd/verifyCode/main.go
@@ -2,7 +2,10 @@ package main
 
 import (
 	"flag"
+	"math/rand"
+
 	"os"
+	"time"
 
 	"verifyCode/internal/conf"
 
@@ -79,7 +82,7 @@ func main() {
 		panic(err)
 	}
 	defer cleanup()
-
+	rand.Seed(time.Now().UnixNano())
 	// start and wait for stop signal
 	if err := app.Run(); err != nil {
 		panic(err)
diff --git a/backend/verifyCode/go.sum b/backend/verifyCode/go.sum
index 8f9d6f8..0a4af2d 100644
--- a/backend/verifyCode/go.sum
+++ b/backend/verifyCode/go.sum
@@ -33,7 +33,6 @@ github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
 github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
-github.com/google/subcommands v1.2.0 h1:vWQspBTo2nEqTUFita5/KeEWlUL8kQObDFbub/EN9oE=
 github.com/google/subcommands v1.2.0/go.mod h1:ZjhPrFU+Olkh9WazFPsl27BQ4UPiG37m3yTrtFlrHVk=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
@@ -71,7 +70,6 @@ golang.org/x/crypto v0.18.0/go.mod h1:R0j02AL6hcrfOiy9T4ZYp/rcWeMxM3L6QYxlOuEG1m
 golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4=
 golang.org/x/mod v0.8.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
 golang.org/x/mod v0.12.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
-golang.org/x/mod v0.14.0 h1:dGoOF9QVLYng8IHTm7BAyWqCqSheQ5pYWGhzW00YJr0=
 golang.org/x/mod v0.14.0/go.mod h1:hTbmBsO62+eylJbnUtE2MGJUyE7QWk4xUqPFrRgJ+7c=
 golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
@@ -121,7 +119,6 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.1.12/go.mod h1:hNGJHUnrk76NpqgfD5Aqm5Crs+Hm0VOH/i9J2+nxYbc=
 golang.org/x/tools v0.6.0/go.mod h1:Xwgl3UAJ/d3gWutnCtw505GrjyAbvKui8lOU390QaIU=
 golang.org/x/tools v0.13.0/go.mod h1:HvlwmtVNQAhOuCjW7xxvovg8wbNq7LwfXh/k7wXUl58=
-golang.org/x/tools v0.17.0 h1:FvmRgNOcs3kOa+T20R1uhfP9F6HgG2mfxDv1vrx1Htc=
 golang.org/x/tools v0.17.0/go.mod h1:xsh6VxdV005rRVaS6SSAf9oiAqljS7UZUacMZ8Bnsps=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/genproto/googleapis/api v0.0.0-20240528184218-531527333157 h1:7whR9kGa5LUwFtpLm2ArCEejtnxlGeLbAyjFY8sGNFw=
diff --git a/backend/verifyCode/idxBits b/backend/verifyCode/idxBits
new file mode 100644
index 0000000..e69de29
diff --git a/backend/verifyCode/internal/service/verifycode.go b/backend/verifyCode/internal/service/verifycode.go
index b85f068..b1d68bc 100644
--- a/backend/verifyCode/internal/service/verifycode.go
+++ b/backend/verifyCode/internal/service/verifycode.go
@@ -2,7 +2,8 @@ package service
 
 import (
 	"context"
-
+	"math/rand"
+	"strings"
 	pb "verifyCode/api/verifyCode"
 )
 
@@ -16,6 +17,52 @@ func NewVerifyCodeService() *VerifyCodeService {
 
 func (s *VerifyCodeService) GetVerifyCode(ctx context.Context, req *pb.GetVerifyCodeRequest) (*pb.GetVerifyCodeReply, error) {
 	return &pb.GetVerifyCodeReply{
-		Code: "MSb",
+		Code: RandCode(int(req.Length), req.Type),
 	}, nil
 }
+
+// 随机数简单生成 RandCode(int(req.Length), req.Type)
+func RandCode(l int, t pb.TYPE) string {
+	switch t {
+	case pb.TYPE_DEFAULT:
+		fallthrough
+	case pb.TYPE_DIGIT:
+		return randCode("123456789", 4, l)
+	case pb.TYPE_MIXED:
+		return randCode("abcdefghijklmnopqrstuvwxyz", 5, l)
+	case pb.TYPE_LETTER:
+		return randCode("123456789abcdefghijklmnopqrstuvwxyz", 6, l)
+	}
+	return ""
+}
+func randCode(chars string, idxBits, l int) string {
+	// 形成掩码
+	idxMask := 1<<idxBits - 1
+	// 63 位可以使用的最大组次数
+	idxMax := 63 / idxBits
+
+	// 利用string builder构建结果缓冲
+	sb := strings.Builder{}
+	sb.Grow(l)
+
+	// 循环生成随机数
+	// i 索引
+	// cache 随机数缓存
+	// remain 随机数还可以用几次
+	for i, cache, remain := l-1, rand.Int63(), idxMax; i >= 0; {
+		// 随机缓存不足，重新生成
+		if remain == 0 {
+			cache, remain = rand.Int63(), idxMax
+		}
+		// 利用掩码生成随机索引，有效索引为小于字符集合长度
+		if idx := int(cache & int64(idxMask)); idx < len(chars) {
+			sb.WriteByte(chars[idx])
+			i--
+		}
+		// 利用下一组随机数位
+		cache >>= idxBits
+		remain--
+	}
+
+	return sb.String()
+}