diff --git a/_mocks/opencsg.com/csghub-server/builder/git/gitserver/mock_GitServer.go b/_mocks/opencsg.com/csghub-server/builder/git/gitserver/mock_GitServer.go
index f9623447d..84fc259d6 100644
--- a/_mocks/opencsg.com/csghub-server/builder/git/gitserver/mock_GitServer.go
+++ b/_mocks/opencsg.com/csghub-server/builder/git/gitserver/mock_GitServer.go
@@ -2399,6 +2399,53 @@ func (_c *MockGitServer_RepositoryExists_Call) RunAndReturn(run func(context.Con
 	return _c
 }
 
+// SetDefaultBranch provides a mock function with given fields: ctx, req
+func (_m *MockGitServer) SetDefaultBranch(ctx context.Context, req gitserver.SetDefaultBranchReq) error {
+	ret := _m.Called(ctx, req)
+
+	if len(ret) == 0 {
+		panic("no return value specified for SetDefaultBranch")
+	}
+
+	var r0 error
+	if rf, ok := ret.Get(0).(func(context.Context, gitserver.SetDefaultBranchReq) error); ok {
+		r0 = rf(ctx, req)
+	} else {
+		r0 = ret.Error(0)
+	}
+
+	return r0
+}
+
+// MockGitServer_SetDefaultBranch_Call is a *mock.Call that shadows Run/Return methods with type explicit version for method 'SetDefaultBranch'
+type MockGitServer_SetDefaultBranch_Call struct {
+	*mock.Call
+}
+
+// SetDefaultBranch is a helper method to define mock.On call
+//   - ctx context.Context
+//   - req gitserver.SetDefaultBranchReq
+func (_e *MockGitServer_Expecter) SetDefaultBranch(ctx interface{}, req interface{}) *MockGitServer_SetDefaultBranch_Call {
+	return &MockGitServer_SetDefaultBranch_Call{Call: _e.mock.On("SetDefaultBranch", ctx, req)}
+}
+
+func (_c *MockGitServer_SetDefaultBranch_Call) Run(run func(ctx context.Context, req gitserver.SetDefaultBranchReq)) *MockGitServer_SetDefaultBranch_Call {
+	_c.Call.Run(func(args mock.Arguments) {
+		run(args[0].(context.Context), args[1].(gitserver.SetDefaultBranchReq))
+	})
+	return _c
+}
+
+func (_c *MockGitServer_SetDefaultBranch_Call) Return(_a0 error) *MockGitServer_SetDefaultBranch_Call {
+	_c.Call.Return(_a0)
+	return _c
+}
+
+func (_c *MockGitServer_SetDefaultBranch_Call) RunAndReturn(run func(context.Context, gitserver.SetDefaultBranchReq) error) *MockGitServer_SetDefaultBranch_Call {
+	_c.Call.Return(run)
+	return _c
+}
+
 // UpdateOrganization provides a mock function with given fields: _a0, _a1
 func (_m *MockGitServer) UpdateOrganization(_a0 *types.EditOrgReq, _a1 *database.Organization) (*database.Organization, error) {
 	ret := _m.Called(_a0, _a1)
diff --git a/builder/git/gitserver/gitaly/branch.go b/builder/git/gitserver/gitaly/branch.go
index 116b3264e..ab3438058 100644
--- a/builder/git/gitserver/gitaly/branch.go
+++ b/builder/git/gitserver/gitaly/branch.go
@@ -176,3 +176,28 @@ func (c *Client) CreateBranch(ctx context.Context, req gitserver.CreateBranchReq
 	}
 	return nil
 }
+
+func (c *Client) SetDefaultBranch(ctx context.Context, req gitserver.SetDefaultBranchReq) error {
+	repoType := fmt.Sprintf("%ss", string(req.RepoType))
+	relativePath, err := c.BuildRelativePath(ctx, req.RepoType, req.Namespace, req.Name)
+	if err != nil {
+		return err
+	}
+	_, err = c.repoClient.WriteRef(ctx, &gitalypb.WriteRefRequest{
+		Repository: &gitalypb.Repository{
+			StorageName:  c.config.GitalyServer.Storage,
+			RelativePath: relativePath,
+			GlRepository: filepath.Join(repoType, req.Namespace, req.Name),
+		},
+		Ref:      []byte("HEAD"),
+		Revision: []byte("refs/heads/" + req.BranchName),
+	})
+	if err != nil {
+		return errorx.SetDefaultBranchFailed(err, errorx.Ctx().
+			Set("repo_type", req.RepoType).
+			Set("path", relativePath).
+			Set("branch", req.BranchName),
+		)
+	}
+	return nil
+}
diff --git a/builder/git/gitserver/gitea/branch.go b/builder/git/gitserver/gitea/branch.go
index 1647e62e6..a22794f76 100644
--- a/builder/git/gitserver/gitea/branch.go
+++ b/builder/git/gitserver/gitea/branch.go
@@ -66,3 +66,7 @@ func (c *Client) DeleteRepoBranch(ctx context.Context, req gitserver.DeleteBranc
 func (c *Client) CreateBranch(ctx context.Context, req gitserver.CreateBranchReq) error {
 	return nil
 }
+
+func (c *Client) SetDefaultBranch(ctx context.Context, req gitserver.SetDefaultBranchReq) error {
+	return nil
+}
diff --git a/builder/git/gitserver/interface.go b/builder/git/gitserver/interface.go
index b873af573..0095af748 100644
--- a/builder/git/gitserver/interface.go
+++ b/builder/git/gitserver/interface.go
@@ -30,6 +30,7 @@ type GitServer interface {
 	GetRepoBranches(ctx context.Context, req GetBranchesReq) ([]types.Branch, error)
 	GetRepoBranchByName(ctx context.Context, req GetBranchReq) (*types.Branch, error)
 	DeleteRepoBranch(ctx context.Context, req DeleteBranchReq) error
+	SetDefaultBranch(ctx context.Context, req SetDefaultBranchReq) error
 	GetRepoCommits(ctx context.Context, req GetRepoCommitsReq) ([]types.Commit, *types.RepoPageOpts, error)
 	GetRepoLastCommit(ctx context.Context, req GetRepoLastCommitReq) (*types.Commit, error)
 	GetSingleCommit(ctx context.Context, req GetRepoLastCommitReq) (*types.CommitResponse, error)
diff --git a/builder/git/gitserver/types.go b/builder/git/gitserver/types.go
index 9b750d6f2..0826115f6 100644
--- a/builder/git/gitserver/types.go
+++ b/builder/git/gitserver/types.go
@@ -108,6 +108,13 @@ type CreateBranchReq struct {
 	RepoType   types.RepositoryType `json:"repo_type"`
 }
 
+type SetDefaultBranchReq struct {
+	Namespace  string               `json:"namespace"`
+	Name       string               `json:"name"`
+	BranchName string               `json:"branch_name"`
+	RepoType   types.RepositoryType `json:"repo_type"`
+}
+
 type GetBranchReq struct {
 	Namespace string               `json:"namespace"`
 	Name      string               `json:"name"`
diff --git a/common/errorx/error_git.go b/common/errorx/error_git.go
index 329b855ba..d8d786c31 100644
--- a/common/errorx/error_git.go
+++ b/common/errorx/error_git.go
@@ -20,6 +20,7 @@ const (
 	gitBranchNotFound
 	gitDeleteBranchFailed
 	gitCreateBranchFailed
+	gitSetDefaultBranchFailed
 	gitFileNotFound
 	gitUploadFailed
 	gitDownloadFailed
@@ -565,6 +566,15 @@ func CreateBranchFailed(err error, ctx context) error {
 	}
 }
 
+func SetDefaultBranchFailed(err error, ctx context) error {
+	return CustomError{
+		prefix:  errGitPrefix,
+		code:    gitSetDefaultBranchFailed,
+		err:     err,
+		context: ctx,
+	}
+}
+
 func GitFileNotFound(err error, ctx context) error {
 	return CustomError{
 		prefix:  errGitPrefix,