diff --git a/cmd/server/integration_job_test.go b/cmd/server/integration_job_test.go
index 172505c..a245543 100644
--- a/cmd/server/integration_job_test.go
+++ b/cmd/server/integration_job_test.go
@@ -3,7 +3,6 @@ package main
 import (
 	"bytes"
 	"encoding/json"
-	"fmt"
 	"net/http"
 	"testing"
 
@@ -66,6 +65,8 @@ func jobSubmitViaAPI(t *testing.T, env *testenv.TestEnv, script string) int32 {
 	return job.JobID
 }
 
+// [已弃用] 以下测试依赖 POST /api/v1/jobs/submit，该接口已被 POST /tasks 取代。
+/*
 // TestIntegration_Jobs_Submit verifies POST /api/v1/jobs/submit creates a new job.
 func TestIntegration_Jobs_Submit(t *testing.T) {
 	env := testenv.NewTestEnv(t)
@@ -220,3 +221,4 @@ func TestIntegration_Jobs_History(t *testing.T) {
 		t.Fatalf("cancelled job %d not found in history", jobID)
 	}
 }
+*/
diff --git a/cmd/server/main_test.go b/cmd/server/main_test.go
index 7ef17ea..629e498 100644
--- a/cmd/server/main_test.go
+++ b/cmd/server/main_test.go
@@ -53,7 +53,7 @@ func TestRouterRegistration(t *testing.T) {
 		method string
 		path   string
 	}{
-		{"POST", "/api/v1/jobs/submit"},
+		// {"POST", "/api/v1/jobs/submit"}, // [已弃用] 已被 POST /tasks 取代
 		{"GET", "/api/v1/jobs"},
 		{"GET", "/api/v1/jobs/history"},
 		{"GET", "/api/v1/jobs/:id"},
diff --git a/internal/handler/job.go b/internal/handler/job.go
index 18c8c74..6954bba 100644
--- a/internal/handler/job.go
+++ b/internal/handler/job.go
@@ -22,29 +22,31 @@ func NewJobHandler(jobSvc *service.JobService, logger *zap.Logger) *JobHandler {
 	return &JobHandler{jobSvc: jobSvc, logger: logger}
 }
 
+// [已弃用] SubmitJob 已被 POST /tasks 取代。
+// 保留方法体以防需要回滚。
 // SubmitJob handles POST /api/v1/jobs/submit.
-func (h *JobHandler) SubmitJob(c *gin.Context) {
-	var req model.SubmitJobRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		h.logger.Warn("bad request", zap.String("method", "SubmitJob"), zap.String("error", "invalid request body"))
-		server.BadRequest(c, "invalid request body")
-		return
-	}
-	if req.Script == "" {
-		h.logger.Warn("bad request", zap.String("method", "SubmitJob"), zap.String("error", "script is required"))
-		server.BadRequest(c, "script is required")
-		return
-	}
-
-	resp, err := h.jobSvc.SubmitJob(c.Request.Context(), &req)
-	if err != nil {
-		h.logger.Error("handler error", zap.String("method", "SubmitJob"), zap.Int("status", http.StatusBadGateway), zap.Error(err))
-		server.ErrorWithStatus(c, http.StatusBadGateway, "slurm error: "+err.Error())
-		return
-	}
-
-	server.Created(c, resp)
-}
+// func (h *JobHandler) SubmitJob(c *gin.Context) {
+// 	var req model.SubmitJobRequest
+// 	if err := c.ShouldBindJSON(&req); err != nil {
+// 		h.logger.Warn("bad request", zap.String("method", "SubmitJob"), zap.String("error", "invalid request body"))
+// 		server.BadRequest(c, "invalid request body")
+// 		return
+// 	}
+// 	if req.Script == "" {
+// 		h.logger.Warn("bad request", zap.String("method", "SubmitJob"), zap.String("error", "script is required"))
+// 		server.BadRequest(c, "script is required")
+// 		return
+// 	}
+//
+// 	resp, err := h.jobSvc.SubmitJob(c.Request.Context(), &req)
+// 	if err != nil {
+// 		h.logger.Error("handler error", zap.String("method", "SubmitJob"), zap.Int("status", http.StatusBadGateway), zap.Error(err))
+// 		server.ErrorWithStatus(c, http.StatusBadGateway, "slurm error: "+err.Error())
+// 		return
+// 	}
+//
+// 	server.Created(c, resp)
+// }
 
 // GetJobs handles GET /api/v1/jobs with pagination.
 func (h *JobHandler) GetJobs(c *gin.Context) {
diff --git a/internal/handler/job_test.go b/internal/handler/job_test.go
index a33689d..61e43e4 100644
--- a/internal/handler/job_test.go
+++ b/internal/handler/job_test.go
@@ -1,9 +1,7 @@
 package handler
 
 import (
-	"bytes"
 	"encoding/json"
-	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -23,7 +21,7 @@ func setupJobRouter(h *JobHandler) *gin.Engine {
 	v1 := r.Group("/api/v1")
 	jobs := v1.Group("/jobs")
 	{
-		jobs.POST("/submit", h.SubmitJob)
+		// jobs.POST("/submit", h.SubmitJob) // [已弃用] 已被 POST /tasks 取代
 		jobs.GET("", h.GetJobs)
 		jobs.GET("/history", h.GetJobHistory)
 		jobs.GET("/:id", h.GetJob)
@@ -61,6 +59,8 @@ func handlerLogs(logs *observer.ObservedLogs) []observer.LoggedEntry {
 	return handler
 }
 
+// [已弃用] SubmitJob 相关测试已被禁用，该接口已被 POST /tasks 取代。
+/*
 func TestSubmitJob_Success(t *testing.T) {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/slurm/v0.0.40/job/submit", func(w http.ResponseWriter, r *http.Request) {
@@ -171,6 +171,9 @@ func TestSubmitJob_SlurmError(t *testing.T) {
 		t.Fatalf("expected 502, got %d: %s", w.Code, w.Body.String())
 	}
 }
+*/
+
+// --- Logging verification tests ---
 
 func TestGetJobs_Success(t *testing.T) {
 	mux := http.NewServeMux()
@@ -462,6 +465,7 @@ func TestGetJobHistory_DefaultPagination(t *testing.T) {
 	}
 }
 
+/*
 func TestSubmitJob_InvalidBody(t *testing.T) {
 	mux := http.NewServeMux()
 	srv, handler := setupJobHandler(mux)
@@ -479,9 +483,11 @@ func TestSubmitJob_InvalidBody(t *testing.T) {
 		t.Fatalf("expected 400, got %d: %s", w.Code, w.Body.String())
 	}
 }
+*/
 
 // --- Logging verification tests ---
 
+/*
 func TestSubmitJob_InvalidBody_LogsWarn(t *testing.T) {
 	mux := http.NewServeMux()
 	srv, handler, logs := setupJobHandlerWithObserver(mux)
@@ -614,6 +620,7 @@ func TestSubmitJob_Success_NoHandlerLogs(t *testing.T) {
 		t.Errorf("expected no handler log entries on success, got %d", len(hLogs))
 	}
 }
+*/
 
 func TestGetJobs_Error_LogsError(t *testing.T) {
 	mux := http.NewServeMux()
diff --git a/internal/server/server.go b/internal/server/server.go
index 86141ac..187f52f 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -10,7 +10,7 @@ import (
 )
 
 type JobHandler interface {
-	SubmitJob(c *gin.Context)
+	// SubmitJob(c *gin.Context) // [已弃用] 已被 POST /tasks 取代
 	GetJobs(c *gin.Context)
 	GetJobHistory(c *gin.Context)
 	GetJob(c *gin.Context)
@@ -73,7 +73,7 @@ func NewRouter(jobH JobHandler, clusterH ClusterHandler, appH ApplicationHandler
 	v1 := r.Group("/api/v1")
 
 	jobs := v1.Group("/jobs")
-	jobs.POST("/submit", jobH.SubmitJob)
+	// jobs.POST("/submit", jobH.SubmitJob) // [已弃用] 已被 POST /tasks 取代
 	jobs.GET("", jobH.GetJobs)
 	jobs.GET("/history", jobH.GetJobHistory)
 	jobs.GET("/:id", jobH.GetJob)
@@ -144,7 +144,7 @@ func NewTestRouter() *gin.Engine {
 
 func registerPlaceholderRoutes(v1 *gin.RouterGroup) {
 	jobs := v1.Group("/jobs")
-	jobs.POST("/submit", notImplemented)
+	// jobs.POST("/submit", notImplemented) // [已弃用] 已被 POST /tasks 取代
 	jobs.GET("", notImplemented)
 	jobs.GET("/history", notImplemented)
 	jobs.GET("/:id", notImplemented)
diff --git a/internal/server/server_test.go b/internal/server/server_test.go
index 9aa51ec..56ecd78 100644
--- a/internal/server/server_test.go
+++ b/internal/server/server_test.go
@@ -17,7 +17,7 @@ func TestAllRoutesRegistered(t *testing.T) {
 		method string
 		path   string
 	}{
-		{"POST", "/api/v1/jobs/submit"},
+		// {"POST", "/api/v1/jobs/submit"}, // [已弃用] 已被 POST /tasks 取代
 		{"GET", "/api/v1/jobs"},
 		{"GET", "/api/v1/jobs/history"},
 		{"GET", "/api/v1/jobs/:id"},
diff --git a/internal/service/task_service.go b/internal/service/task_service.go
index 8a8d031..ef344c1 100644
--- a/internal/service/task_service.go
+++ b/internal/service/task_service.go
@@ -263,7 +263,15 @@ func (s *TaskService) ProcessTask(ctx context.Context, taskID int64) error {
 		}
 	}
 
-	// 13-14. Set ready + submitting
+	// 13-14. Set ready + submitting (guard: skip if already submitted to Slurm)
+	if task.SlurmJobID != nil {
+		s.logger.Info("task already has slurm job, skipping submission",
+			zap.Int64("task_id", taskID),
+			zap.Int32("slurm_job_id", *task.SlurmJobID),
+		)
+		return nil
+	}
+
 	if err := s.taskStore.UpdateRetryState(ctx, taskID, model.TaskStatusReady, model.TaskStepSubmitting, 0); err != nil {
 		return fail(model.TaskStepSubmitting, fmt.Sprintf("update status to ready: %v", err))
 	}
@@ -694,6 +702,13 @@ func (s *TaskService) RecoverStuckTasks(ctx context.Context) {
 		return
 	}
 	for i := range tasks {
+		if tasks[i].SlurmJobID != nil {
+			s.logger.Info("skipping stuck task recovery, already in slurm",
+				zap.Int64("taskID", tasks[i].ID),
+				zap.Int32("slurm_job_id", *tasks[i].SlurmJobID),
+			)
+			continue
+		}
 		_ = s.taskStore.UpdateStatus(ctx, tasks[i].ID, model.TaskStatusSubmitted, "")
 		s.mu.Lock()
 		if !s.stopped {
diff --git a/internal/testutil/testenv/env_test.go b/internal/testutil/testenv/env_test.go
index 81c3d0f..68c8b15 100644
--- a/internal/testutil/testenv/env_test.go
+++ b/internal/testutil/testenv/env_test.go
@@ -49,7 +49,7 @@ func TestAllRoutesRegistered(t *testing.T) {
 		method string
 		path   string
 	}{
-		{"POST", "/api/v1/jobs/submit"},
+		// {"POST", "/api/v1/jobs/submit"}, // [已弃用] 已被 POST /tasks 取代
 		{"GET", "/api/v1/jobs"},
 		{"GET", "/api/v1/jobs/history"},
 		{"GET", "/api/v1/jobs/1"},
@@ -82,8 +82,8 @@ func TestAllRoutesRegistered(t *testing.T) {
 		{"GET", "/api/v1/tasks"},
 	}
 
-	if len(routes) != 30 {
-		t.Fatalf("expected 31 routes, got %d", len(routes))
+	if len(routes) != 29 {
+		t.Fatalf("expected 30 routes, got %d", len(routes))
 	}
 
 	for _, r := range routes {