diff --git a/backend/internal/httpapi/resource_scope_test.go b/backend/internal/httpapi/resource_scope_test.go
index 74cc2db..4d80baf 100644
--- a/backend/internal/httpapi/resource_scope_test.go
+++ b/backend/internal/httpapi/resource_scope_test.go
@@ -30,7 +30,12 @@ func TestDomainResourceScopeAPI(t *testing.T) {
 		}
 	}
 	repo := repository.NewSQLDomainRepository(db.DB)
-	server := New(Dependencies{Config: cfg, Repository: repo, ProjectDomains: repository.NewSQLProjectMemberRepository(db.DB)})
+	projectResources := repository.NewSQLProjectMemberRepository(db.DB)
+	server := New(Dependencies{
+		Config: cfg, Repository: repo,
+		ProjectResources: projectResources,
+		ProjectDomains:   projectResources,
+	})
 	request := func(method, path, body, user string) *httptest.ResponseRecorder {
 		req := httptest.NewRequest(method, path, strings.NewReader(body))
 		req.Header.Set("Content-Type", "application/json")
diff --git a/backend/internal/httpapi/review_test.go b/backend/internal/httpapi/review_test.go
index a937088..6d213e7 100644
--- a/backend/internal/httpapi/review_test.go
+++ b/backend/internal/httpapi/review_test.go
@@ -150,7 +150,11 @@ func TestDomainAPIValidatesSANAndHidesInternalErrors(t *testing.T) {
 func TestDeleteMissingDomainReturnsNotFound(t *testing.T) {
 	cfg := readyTestConfig(t.TempDir())
 	repo := &stubDomainRepository{deleteErr: sql.ErrNoRows}
-	server := New(Dependencies{Config: cfg, Repository: repo, ProjectDomains: projectDomainRepositoryStub{DomainRepository: repo}})
+	server := New(Dependencies{
+		Config: cfg, Repository: repo,
+		ProjectResources: projectResourceReaderStub{domains: repo},
+		ProjectDomains:   projectDomainRepositoryStub{DomainRepository: repo},
+	})
 	response := httptest.NewRecorder()
 	serveAdminHTTP(server, response, httptest.NewRequest(http.MethodDelete, "/api/v1/domains/missing", nil))
 	if response.Code != http.StatusNotFound || strings.Contains(response.Body.String(), "detail") {
@@ -162,7 +166,11 @@ func TestUpdateDomainAPI(t *testing.T) {
 	cfg := readyTestConfig(t.TempDir())
 	loaded := domain.Domain{ID: "domain-1", Name: "example.com", CertificateType: domain.CertificateSingle, SANs: []string{"example.com"}, Status: "active"}
 	repo := &stubDomainRepository{loaded: loaded}
-	server := New(Dependencies{Config: cfg, Repository: repo, ProjectDomains: projectDomainRepositoryStub{DomainRepository: repo}})
+	server := New(Dependencies{
+		Config: cfg, Repository: repo,
+		ProjectResources: projectResourceReaderStub{domains: repo},
+		ProjectDomains:   projectDomainRepositoryStub{DomainRepository: repo},
+	})
 	request := httptest.NewRequest(http.MethodPut, "/api/v1/domains/domain-1", strings.NewReader(`{"name":"example.com","certificate_type":"san","sans":["www.example.com"],"auto_renew":false,"acme_environment":"production","dns_provider":"cloudflare"}`))
 	request.Header.Set("Content-Type", "application/json")
 	response := httptest.NewRecorder()
@@ -192,7 +200,11 @@ func TestUpdateDomainRejectsInvalidEnvironment(t *testing.T) {
 	cfg := readyTestConfig(t.TempDir())
 	loaded := domain.Domain{ID: "domain-1", Name: "example.com"}
 	repo := &stubDomainRepository{loaded: loaded}
-	server := New(Dependencies{Config: cfg, Repository: repo, ProjectDomains: projectDomainRepositoryStub{DomainRepository: repo}})
+	server := New(Dependencies{
+		Config: cfg, Repository: repo,
+		ProjectResources: projectResourceReaderStub{domains: repo},
+		ProjectDomains:   projectDomainRepositoryStub{DomainRepository: repo},
+	})
 	request := httptest.NewRequest(http.MethodPut, "/api/v1/domains/domain-1", strings.NewReader(`{"name":"example.com","certificate_type":"single","acme_environment":"invalid"}`))
 	request.Header.Set("Content-Type", "application/json")
 	response := httptest.NewRecorder()
diff --git a/backend/internal/httpapi/server.go b/backend/internal/httpapi/server.go
index 561b171..4a52815 100644
--- a/backend/internal/httpapi/server.go
+++ b/backend/internal/httpapi/server.go
@@ -602,7 +602,7 @@ func (s *Server) createDomain(c *gin.Context) {
 }
 
 func (s *Server) updateDomain(c *gin.Context) {
-	if !s.requireProjectDomainRepository(c) || !s.requireDomainRepository(c) {
+	if !s.requireProjectDomainRepository(c) || !s.requireProjectResourceReader(c) {
 		return
 	}
 	var request domainRequest
@@ -610,13 +610,9 @@ func (s *Server) updateDomain(c *gin.Context) {
 		s.writeError(c, http.StatusBadRequest, "请求参数无效", err)
 		return
 	}
-	existing, err := s.repository.GetByID(c.Request.Context(), c.Param("id"))
+	existing, err := s.projectResources.GetVisibleDomain(c.Request.Context(), c.GetString(authenticatedActorKey), c.Param("id"))
 	if err != nil {
-		if repository.IsNotFound(err) {
-			s.writeError(c, http.StatusNotFound, "域名不存在", err)
-			return
-		}
-		s.writeError(c, http.StatusInternalServerError, "读取域名失败", err)
+		s.writeProjectResourceError(c, err)
 		return
 	}
 	if !s.authorizeDomainMutation(c, existing.ProjectID) {
diff --git a/backend/internal/repository/task_repository.go b/backend/internal/repository/task_repository.go
index d829d12..3645cdb 100644
--- a/backend/internal/repository/task_repository.go
+++ b/backend/internal/repository/task_repository.go
@@ -88,26 +88,52 @@ func (r *SQLTaskRepository) CreateTask(ctx context.Context, item Task) error {
 		item.ID, item.DomainID, item.TaskType, item.Status, item.Stage, item.Message, item.OperatorID,
 		item.CertificateVersionID, item.IdempotencyKey, nullableTime(item.StartedAt), nullableTime(item.FinishedAt), now, updated,
 	}
-	query := `INSERT INTO tasks
+	insertQuery := `INSERT INTO tasks
 		(id, domain_id, task_type, status, stage, message, operator_id, certificate_version_id, idempotency_key, started_at, finished_at, created_at, updated_at, scope_type, project_id) `
 	if item.TaskType == "management_renewal" {
 		if item.DomainID != ManagementResourceID || !item.HistoryScope.matches(HistoryScope{ScopeType: ScopeSystem}) {
 			return errors.New("管理证书任务范围无效")
 		}
-		query += `VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'system', '')`
-	} else {
-		if item.DomainID == ManagementResourceID || (item.ScopeType != "" && item.ScopeType != ScopeProject) {
-			return errors.New("业务任务必须归属于实际域名项目")
+		result, err := r.db.ExecContext(ctx, r.query(insertQuery+`VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'system', '')`), args...)
+		if err != nil {
+			return fmt.Errorf("创建任务失败：%w", err)
 		}
-		// 一条语句读取资源归属并写入快照，不能先检查再插入悬空任务。
-		query += `SELECT ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'project', d.project_id
-			FROM domains d JOIN projects p ON p.id = d.project_id WHERE d.id = ? AND (? = '' OR d.project_id = ?)`
-		args = append(args, item.DomainID, item.ProjectID, item.ProjectID)
+		return validateTaskInsertResult(result)
 	}
-	result, err := r.db.ExecContext(ctx, r.query(query), args...)
+	if item.DomainID == ManagementResourceID || (item.ScopeType != "" && item.ScopeType != ScopeProject) {
+		return errors.New("业务任务必须归属于实际域名项目")
+	}
+
+	// 创建任务与删除域名使用相同的域名行锁，避免删除检查完成后又插入在途任务。
+	tx, err := r.db.BeginTx(ctx, nil)
+	if err != nil {
+		return fmt.Errorf("开始任务创建事务失败：%w", err)
+	}
+	defer tx.Rollback()
+	var projectID string
+	if err := tx.QueryRowContext(ctx, r.query(`SELECT d.project_id FROM domains d
+		JOIN projects p ON p.id = d.project_id WHERE d.id = ? AND (? = '' OR d.project_id = ?)`+taskResourceWriteLock(r.driver)),
+		item.DomainID, item.ProjectID, item.ProjectID).Scan(&projectID); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return errors.New("任务资源不存在或项目不匹配")
+		}
+		return fmt.Errorf("读取任务所属域名失败：%w", err)
+	}
+	args = append(args, projectID)
+	result, err := tx.ExecContext(ctx, r.query(insertQuery+`VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, 'project', ?)`), args...)
 	if err != nil {
 		return fmt.Errorf("创建任务失败：%w", err)
 	}
+	if err := validateTaskInsertResult(result); err != nil {
+		return err
+	}
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("提交任务创建事务失败：%w", err)
+	}
+	return nil
+}
+
+func validateTaskInsertResult(result sql.Result) error {
 	if count, err := result.RowsAffected(); err != nil {
 		return fmt.Errorf("读取任务创建结果失败：%w", err)
 	} else if count != 1 {
@@ -116,6 +142,15 @@ func (r *SQLTaskRepository) CreateTask(ctx context.Context, item Task) error {
 	return nil
 }
 
+func taskResourceWriteLock(driver string) string {
+	switch driver {
+	case "mysql", "postgres":
+		return " FOR UPDATE"
+	default:
+		return ""
+	}
+}
+
 func (r *SQLTaskRepository) GetTask(ctx context.Context, id string) (Task, error) {
 	if r == nil || r.db == nil {
 		return Task{}, errors.New("数据库连接不能为空")