diff --git a/apps/api/app/api/routes/ingest_jobs.py b/apps/api/app/api/routes/ingest_jobs.py
index b7148ae93..791be8964 100644
--- a/apps/api/app/api/routes/ingest_jobs.py
+++ b/apps/api/app/api/routes/ingest_jobs.py
@@ -3,7 +3,7 @@ from typing import Any
 from app.core.celery_app import celery_app
 from app.dependencies import get_ingest_job_repository
 from app.schemas.ingest_job import IngestJobResponse, SubmitIngestJobRequest
-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, HTTPException
 
 from packages.application import SubmitIngestJobCommand, SubmitIngestJobUseCase
 
@@ -17,7 +17,7 @@ def get_ingest_job(
 ) -> IngestJobResponse:
     job = ingest_job_repository.get(job_id)
     if job is None:
-        raise ValueError(f"IngestJob {job_id} not found")
+        raise HTTPException(status_code=404, detail=f"IngestJob {job_id} not found")
     return IngestJobResponse(
         id=job.id,
         project_id=job.project_id,
diff --git a/tests/unit/test_ingest_jobs_route_404.py b/tests/unit/test_ingest_jobs_route_404.py
new file mode 100644
index 000000000..321b4d9e5
--- /dev/null
+++ b/tests/unit/test_ingest_jobs_route_404.py
@@ -0,0 +1,83 @@
+"""Ingest jobs GET route — 查不到 job_id 应返回 404，不是 500。
+
+覆盖：
+- job 不存在：GET /ingest-jobs/{job_id} → 404
+- job 存在：200 + 序列化字段完整
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+from pathlib import Path
+from unittest.mock import MagicMock
+
+os.environ.setdefault("JWT_SECRET_KEY", "unit-test-secret-key-for-testing")
+os.environ.setdefault("DATABASE_URL", "sqlite:///test.db")
+
+import pytest  # noqa: E402
+from fastapi import FastAPI  # noqa: E402
+from fastapi.testclient import TestClient  # noqa: E402
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "apps" / "api"))
+
+from app.api.routes.ingest_jobs import get_ingest_job, router  # noqa: E402
+from app.dependencies import get_ingest_job_repository  # noqa: E402
+
+from packages.domain import IngestJob, IngestJobStatus  # noqa: E402
+
+
+@pytest.fixture
+def fake_job():
+    return IngestJob(
+        id="job-abc",
+        project_id="proj-1",
+        library_id="lib-1",
+        storage_key="key/test.mp4",
+        status=IngestJobStatus.COMPLETED,
+        error_message="",
+        result_asset_id="asset-xyz",
+    )
+
+
+@pytest.fixture
+def client_not_found():
+    app = FastAPI()
+    app.include_router(router, prefix="/ingest-jobs")
+
+    mock_repo = MagicMock()
+    mock_repo.get.return_value = None
+
+    app.dependency_overrides[get_ingest_job_repository] = lambda: mock_repo
+    return TestClient(app)
+
+
+@pytest.fixture
+def client_found(fake_job):
+    app = FastAPI()
+    app.include_router(router, prefix="/ingest-jobs")
+
+    mock_repo = MagicMock()
+    mock_repo.get.return_value = fake_job
+
+    app.dependency_overrides[get_ingest_job_repository] = lambda: mock_repo
+    return TestClient(app)
+
+
+def test_get_ingest_job_not_found_returns_404(client_not_found):
+    """job 不存在时应返回 404，而不是 500 ValueError。"""
+    resp = client_not_found.get("/ingest-jobs/no-such-job")
+    assert resp.status_code == 404, resp.text
+    assert "no-such-job" in resp.json()["detail"]
+
+
+def test_get_ingest_job_found_returns_200(client_found, fake_job):
+    """job 存在时正常 200 + 字段完整。"""
+    resp = client_found.get(f"/ingest-jobs/{fake_job.id}")
+    assert resp.status_code == 200, resp.text
+    body = resp.json()
+    assert body["id"] == fake_job.id
+    assert body["project_id"] == fake_job.project_id
+    assert body["storage_key"] == fake_job.storage_key
+    assert body["status"] == IngestJobStatus.COMPLETED.value
+    assert body["result_asset_id"] == fake_job.result_asset_id