diff --git a/backend/agenteval/intelligent_eval/task_queue.py b/backend/agenteval/intelligent_eval/task_queue.py
index 2c01ef9..114f8e2 100644
--- a/backend/agenteval/intelligent_eval/task_queue.py
+++ b/backend/agenteval/intelligent_eval/task_queue.py
@@ -226,3 +226,47 @@ def get_next_task_with_eval(session: Session) -> Optional[dict]:
             },
         },
     }
+
+
+# ---------------------------------------------------------------------------
+# 卡死恢复（方案③遗留）：assigned 超时重新入队
+# ---------------------------------------------------------------------------
+
+STALE_ASSIGNED_MINUTES = 10
+
+
+def requeue_stale_assigned_tasks(session: Session) -> int:
+    """Requeue tasks that stayed `assigned` too long without completing.
+
+    方案③ worker 由平台触发 openclaw agent（cron=manual-run-...，非真实 cron），
+    fault_tolerance 的 stuck 检测（基于 cron pool busy + last_active_at）不适用。
+    若 agent 中断/失败，任务会永久卡在 `assigned`，scan 只查 pending 不会再入队。
+
+    这里把「assigned 超过 STALE_ASSIGNED_MINUTES 且对应评估仍 executing」的任务
+    重置为 pending（清空认领信息），平台 scan 循环随后会重新触发 worker 重试。
+
+    Returns:
+        重新入队的任务数。
+    """
+    threshold = utc_now() - timedelta(minutes=STALE_ASSIGNED_MINUTES)
+    stale = session.exec(
+        select(IntelligentEvalTaskQueueDB).where(
+            IntelligentEvalTaskQueueDB.status == "assigned",
+            IntelligentEvalTaskQueueDB.assigned_at < threshold,
+        )
+    ).all()
+
+    requeued = 0
+    for task in stale:
+        ev = session.get(IntelligentEvalDB, task.eval_id)
+        if ev is None or ev.status != IntelligentEvalStatus.EXECUTING.value:
+            continue
+        task.status = "pending"
+        task.assigned_cron_id = None
+        task.assigned_at = None
+        task.updated_at = utc_now()
+        requeued += 1
+
+    if requeued:
+        session.commit()
+    return requeued
diff --git a/backend/agenteval/web/app.py b/backend/agenteval/web/app.py
index 4708625..8ae5edb 100644
--- a/backend/agenteval/web/app.py
+++ b/backend/agenteval/web/app.py
@@ -100,8 +100,14 @@ async def _intelligent_eval_scan_loop() -> None:
         try:
             session = get_session()
             try:
-                from agenteval.intelligent_eval.task_queue import scan_and_enqueue_tasks
+                from agenteval.intelligent_eval.task_queue import (
+                    requeue_stale_assigned_tasks,
+                    scan_and_enqueue_tasks,
+                )
 
+                r = requeue_stale_assigned_tasks(session)
+                if r:
+                    _logger.info("卡死恢复：%d 个 assigned 任务重新入队", r)
                 n = scan_and_enqueue_tasks(session)
                 if n:
                     _logger.info("智能评估扫描：入队 %d 个 Worker 任务", n)
diff --git a/tests/unit/test_task_queue_requeue.py b/tests/unit/test_task_queue_requeue.py
new file mode 100644
index 0000000..43b42c0
--- /dev/null
+++ b/tests/unit/test_task_queue_requeue.py
@@ -0,0 +1,94 @@
+"""Stale-assigned requeue tests (worker crash recovery).
+
+方案③ worker 由平台触发 openclaw agent（cron=manual-run，非真实 cron），
+fault_tolerance 的 stuck 检测不适用；任务可能永久卡 assigned。requeue
+把「assigned 超时且评估仍 executing」的任务重置为 pending。
+"""
+from datetime import timedelta
+
+from agenteval.intelligent_eval.models import IntelligentEvalStatus
+from agenteval.intelligent_eval.task_queue import (
+    STALE_ASSIGNED_MINUTES,
+    requeue_stale_assigned_tasks,
+)
+from agenteval.storage.db import (
+    IntelligentEvalDB,
+    IntelligentEvalTaskQueueDB,
+    utc_now,
+)
+from sqlmodel import Session
+
+
+def _make_executing_eval(db_session: Session) -> IntelligentEvalDB:
+    ev = IntelligentEvalDB(
+        name="req-eval",
+        target_id="t1",
+        status=IntelligentEvalStatus.EXECUTING.value,
+        started_at=utc_now(),
+    )
+    db_session.add(ev)
+    db_session.commit()
+    return ev
+
+
+def test_requeue_stale_assigned_task(db_session: Session):
+    ev = _make_executing_eval(db_session)
+    task = IntelligentEvalTaskQueueDB(
+        eval_id=ev.id,
+        status="assigned",
+        priority=1,
+        reason="slot_due",
+        assigned_cron_id="manual-run-x",
+        assigned_at=utc_now() - timedelta(minutes=STALE_ASSIGNED_MINUTES + 5),
+    )
+    db_session.add(task)
+    db_session.commit()
+
+    assert requeue_stale_assigned_tasks(db_session) == 1
+
+    db_session.refresh(task)
+    assert task.status == "pending"
+    assert task.assigned_cron_id is None
+    assert task.assigned_at is None
+
+
+def test_fresh_assigned_not_requeued(db_session: Session):
+    ev = _make_executing_eval(db_session)
+    task = IntelligentEvalTaskQueueDB(
+        eval_id=ev.id,
+        status="assigned",
+        priority=1,
+        reason="slot_due",
+        assigned_cron_id="manual-run-y",
+        assigned_at=utc_now(),  # fresh
+    )
+    db_session.add(task)
+    db_session.commit()
+
+    assert requeue_stale_assigned_tasks(db_session) == 0
+    db_session.refresh(task)
+    assert task.status == "assigned"
+
+
+def test_stale_assigned_non_executing_not_requeued(db_session: Session):
+    ev = IntelligentEvalDB(
+        name="cancelled-eval",
+        target_id="t1",
+        status=IntelligentEvalStatus.CANCELLED.value,
+    )
+    db_session.add(ev)
+    db_session.commit()
+    task = IntelligentEvalTaskQueueDB(
+        eval_id=ev.id,
+        status="assigned",
+        priority=1,
+        reason="slot_due",
+        assigned_cron_id="manual-run-z",
+        assigned_at=utc_now() - timedelta(minutes=STALE_ASSIGNED_MINUTES + 5),
+    )
+    db_session.add(task)
+    db_session.commit()
+
+    assert requeue_stale_assigned_tasks(db_session) == 0
+    db_session.refresh(task)
+    assert task.status == "assigned"