diff --git a/apps/api/internal/httpapi/handlers.go b/apps/api/internal/httpapi/handlers.go
index 373ef97..6d6adda 100644
--- a/apps/api/internal/httpapi/handlers.go
+++ b/apps/api/internal/httpapi/handlers.go
@@ -1598,6 +1598,10 @@ func boolValue(body map[string]any, key string) bool {
 func (s *Server) getTask(w http.ResponseWriter, r *http.Request) {
 	task, err := s.store.GetTask(r.Context(), r.PathValue("taskID"))
 	if err == nil {
+		cancelState := runner.DescribeTaskCancellation(task)
+		task.Cancellable = &cancelState.Cancellable
+		task.Submitted = &cancelState.Submitted
+		task.Message = cancelState.Message
 		writeJSON(w, http.StatusOK, task)
 		return
 	}
diff --git a/apps/api/internal/runner/task_cancel.go b/apps/api/internal/runner/task_cancel.go
index e35400d..600f778 100644
--- a/apps/api/internal/runner/task_cancel.go
+++ b/apps/api/internal/runner/task_cancel.go
@@ -20,6 +20,25 @@ type TaskCancelResult struct {
 	Message     string `json:"message"`
 }
 
+func DescribeTaskCancellation(task store.GatewayTask) TaskCancelResult {
+	if taskCancelTerminalStatus(task.Status) {
+		return taskCancelUnavailable(task, "任务已结束，无法取消")
+	}
+	if strings.TrimSpace(task.RemoteTaskID) != "" {
+		return taskCancelUnavailable(task, "任务已提交上游，当前不可取消，请继续查询结果")
+	}
+	if strings.TrimSpace(task.Status) != "queued" {
+		return taskCancelUnavailable(task, "任务已开始执行，当前阶段不可取消，请继续查询结果")
+	}
+	return TaskCancelResult{
+		TaskID:      task.ID,
+		Cancelled:   false,
+		Cancellable: true,
+		Submitted:   false,
+		Message:     "任务仍在本地队列中，可取消",
+	}
+}
+
 func (s *Service) CancelTask(ctx context.Context, taskID string, user *auth.User) (TaskCancelResult, error) {
 	task, err := s.store.GetTask(ctx, taskID)
 	if err != nil {
diff --git a/apps/api/internal/runner/task_cancel_test.go b/apps/api/internal/runner/task_cancel_test.go
index 15b90aa..680e719 100644
--- a/apps/api/internal/runner/task_cancel_test.go
+++ b/apps/api/internal/runner/task_cancel_test.go
@@ -76,3 +76,26 @@ func TestTaskCancelUnavailableReportsSubmittedFromRemoteTaskID(t *testing.T) {
 		t.Fatalf("remote task id should report submitted: %+v", result)
 	}
 }
+
+func TestDescribeTaskCancellationReportsQueuedTaskAsCancellable(t *testing.T) {
+	result := DescribeTaskCancellation(store.GatewayTask{ID: "task-queued", Status: "queued"})
+
+	if result.TaskID != "task-queued" {
+		t.Fatalf("unexpected task id: %+v", result)
+	}
+	if result.Cancelled || !result.Cancellable || result.Submitted {
+		t.Fatalf("queued local task should be cancellable and not submitted: %+v", result)
+	}
+}
+
+func TestDescribeTaskCancellationReportsRemoteTaskAsSubmitted(t *testing.T) {
+	result := DescribeTaskCancellation(store.GatewayTask{
+		ID:           "task-remote",
+		Status:       "running",
+		RemoteTaskID: "remote-1",
+	})
+
+	if result.Cancelled || result.Cancellable || !result.Submitted {
+		t.Fatalf("remote task should be submitted and non-cancellable: %+v", result)
+	}
+}
diff --git a/apps/api/internal/store/postgres.go b/apps/api/internal/store/postgres.go
index 82b11b1..e06342e 100644
--- a/apps/api/internal/store/postgres.go
+++ b/apps/api/internal/store/postgres.go
@@ -446,6 +446,9 @@ type GatewayTask struct {
 	AsyncMode          bool           `json:"asyncMode"`
 	RiverJobID         int64          `json:"riverJobId,omitempty"`
 	Status             string         `json:"status"`
+	Cancellable        *bool          `json:"cancellable,omitempty"`
+	Submitted          *bool          `json:"submitted,omitempty"`
+	Message            string         `json:"message,omitempty"`
 	AttemptCount       int            `json:"attemptCount"`
 	RemoteTaskID       string         `json:"remoteTaskId,omitempty"`
 	RemoteTaskPayload  map[string]any `json:"remoteTaskPayload,omitempty"`