diff --git a/tests/test_draft_download_failure_kind.py b/tests/test_draft_download_failure_kind.py
new file mode 100644
index 0000000..0535557
--- /dev/null
+++ b/tests/test_draft_download_failure_kind.py
@@ -0,0 +1,247 @@
+"""草稿下载失败分类：404/资源不可用 vs 网络重试耗尽。"""
+from datetime import datetime
+from unittest.mock import MagicMock, patch
+
+import pytest
+import requests
+
+import src.utils.draft_downloader as dd
+from src.utils.video_task_manager import TaskStatus, VideoGenTask, VideoGenTaskManager
+
+
+@pytest.fixture
+def no_sleep():
+    with patch.object(dd, "time") as m_time:
+        m_time.sleep = MagicMock()
+        yield m_time
+
+
+def _task(draft_id: str = "d_fail") -> VideoGenTask:
+    return VideoGenTask(
+        draft_url=f"http://example/openapi?draft_id={draft_id}",
+        draft_id=draft_id,
+        status=TaskStatus.PENDING,
+        created_at=datetime.now(),
+    )
+
+
+class TestFormatDraftDownloadFailureMessage:
+    def test_network_retry_exhausted(self) -> None:
+        result = dd.DraftDownloadResult(
+            ok=False,
+            kind=dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED,
+        )
+        assert (
+            dd.format_draft_download_failure_message(result)
+            == "草稿下载失败: 网络不稳定，已多次重试仍失败，请稍后重试"
+        )
+
+    def test_resource_unavailable_with_http_status(self) -> None:
+        result = dd.DraftDownloadResult(
+            ok=False,
+            kind=dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE,
+            http_status=404,
+        )
+        assert (
+            dd.format_draft_download_failure_message(result)
+            == "草稿下载失败: 草稿或素材不存在/URL无效 (HTTP 404)"
+        )
+
+    def test_local_io(self) -> None:
+        result = dd.DraftDownloadResult(
+            ok=False,
+            kind=dd.DraftDownloadFailureKind.LOCAL_IO,
+        )
+        assert (
+            dd.format_draft_download_failure_message(result)
+            == "草稿下载失败: 本地文件写入失败"
+        )
+
+
+class TestDownloadSingleFileFailureKind:
+    _URL = "https://cdn.example.com/app/output/draft/20251204214904ccb1af38/a.bin"
+
+    def test_404_is_resource_unavailable(self, no_sleep) -> None:
+        bad = MagicMock()
+        bad.status_code = 404
+        bad.close = MagicMock()
+        with patch.object(dd, "requests") as m_req:
+            m_req.get.return_value = bad
+            m_req.exceptions = requests.exceptions
+            with pytest.raises(dd.DraftDownloadAbort) as ei:
+                dd._download_single_file(self._URL, "/tmp/unused")
+            assert ei.value.kind == dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE
+            assert ei.value.http_status == 404
+            assert m_req.get.call_count == 1
+
+    def test_503_exhausted_is_network_retry_exhausted(self, no_sleep) -> None:
+        bad = MagicMock()
+        bad.status_code = 503
+        bad.headers = {}
+        bad.close = MagicMock()
+        with patch.object(dd, "requests") as m_req:
+            m_req.get.return_value = bad
+            m_req.exceptions = requests.exceptions
+            with pytest.raises(dd.DraftDownloadAbort) as ei:
+                dd._download_single_file(self._URL, "/tmp/unused")
+            assert ei.value.kind == dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED
+            assert ei.value.http_status == 503
+            assert m_req.get.call_count == 6
+
+    def test_timeout_exhausted_is_network_retry_exhausted(self, no_sleep) -> None:
+        with patch.object(dd, "requests") as m_req:
+            m_req.get.side_effect = requests.exceptions.ReadTimeout("read timed out")
+            m_req.exceptions = requests.exceptions
+            with pytest.raises(dd.DraftDownloadAbort) as ei:
+                dd._download_single_file(self._URL, "/tmp/unused")
+            assert ei.value.kind == dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED
+            assert m_req.get.call_count == 6
+
+    def test_connection_refused_is_resource_unavailable(self, no_sleep) -> None:
+        with patch.object(dd, "requests") as m_req:
+            m_req.get.side_effect = requests.exceptions.ConnectionError(
+                "Connection refused"
+            )
+            m_req.exceptions = requests.exceptions
+            with pytest.raises(dd.DraftDownloadAbort) as ei:
+                dd._download_single_file(self._URL, "/tmp/unused")
+            assert ei.value.kind == dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE
+            assert m_req.get.call_count == 1
+
+
+class TestDownloadDraftWithResult:
+    def test_invalid_draft_url(self) -> None:
+        result = dd.download_draft_with_result("not-a-url")
+        assert result.ok is False
+        assert result.kind == dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE
+        assert dd.download_draft("not-a-url") is False
+
+    def test_file_list_404(self, no_sleep) -> None:
+        draft_id = "20251204214904ccb1af38"
+        draft_url = f"https://api.example.com/get_draft?draft_id={draft_id}"
+        bad = MagicMock()
+        bad.status_code = 404
+        bad.close = MagicMock()
+        with patch.object(dd, "prepare_target_directory", return_value="/tmp/d"):
+            with patch.object(dd, "dequeue_path"):
+                with patch.object(dd, "requests") as m_req:
+                    m_req.get.return_value = bad
+                    m_req.exceptions = requests.exceptions
+                    result = dd.download_draft_with_result(draft_url)
+        assert result.ok is False
+        assert result.kind == dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE
+        assert result.http_status == 404
+
+    def test_file_list_503_exhausted(self, no_sleep) -> None:
+        draft_id = "20251204214904ccb1af38"
+        draft_url = f"https://api.example.com/get_draft?draft_id={draft_id}"
+        bad = MagicMock()
+        bad.status_code = 503
+        bad.headers = {}
+        bad.close = MagicMock()
+        with patch.object(dd, "_MAX_RETRIES", 2):
+            with patch.object(dd, "prepare_target_directory", return_value="/tmp/d"):
+                with patch.object(dd, "dequeue_path"):
+                    with patch.object(dd, "requests") as m_req:
+                        m_req.get.return_value = bad
+                        m_req.exceptions = requests.exceptions
+                        result = dd.download_draft_with_result(draft_url)
+        assert result.ok is False
+        assert result.kind == dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED
+        assert result.http_status == 503
+
+    def test_bool_api_matches_with_result(self, no_sleep) -> None:
+        draft_id = "20251204214904ccb1af38"
+        draft_url = f"https://api.example.com/get_draft?draft_id={draft_id}"
+        bad = MagicMock()
+        bad.status_code = 404
+        bad.close = MagicMock()
+        with patch.object(dd, "prepare_target_directory", return_value="/tmp/d"):
+            with patch.object(dd, "dequeue_path"):
+                with patch.object(dd, "requests") as m_req:
+                    m_req.get.return_value = bad
+                    m_req.exceptions = requests.exceptions
+                    assert dd.download_draft(draft_url) is False
+                    assert dd.download_draft_with_result(draft_url).ok is False
+
+
+class TestRemoteMaterialFailureKind:
+    def test_404_resource_unavailable(self, no_sleep) -> None:
+        bad = MagicMock()
+        bad.status_code = 404
+        bad.close = MagicMock()
+        with patch.object(dd, "requests") as m_req:
+            m_req.get.return_value = bad
+            m_req.exceptions = requests.exceptions
+            with pytest.raises(dd.DraftDownloadAbort) as ei:
+                dd._download_remote_material_raising(
+                    "https://cdn.example.com/miss.png",
+                    "/tmp",
+                    "images",
+                    "x",
+                    ".png",
+                )
+            assert ei.value.kind == dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE
+            assert ei.value.http_status == 404
+
+    def test_timeout_exhausted_network(self, no_sleep) -> None:
+        with patch.object(dd, "_MAX_RETRIES", 1):
+            with patch.object(dd, "requests") as m_req:
+                m_req.get.side_effect = requests.exceptions.ReadTimeout("t")
+                m_req.exceptions = requests.exceptions
+                with pytest.raises(dd.DraftDownloadAbort) as ei:
+                    dd._download_remote_material_raising(
+                        "https://cdn.example.com/x.mp4",
+                        "/tmp",
+                        "videos",
+                        "c",
+                        ".mp4",
+                    )
+                assert ei.value.kind == dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED
+
+
+class TestVideoTaskManagerDownloadMessages:
+    @patch("src.utils.video_task_manager.sys.platform", "win32")
+    def test_resource_unavailable_message(self) -> None:
+        result = dd.DraftDownloadResult(
+            ok=False,
+            kind=dd.DraftDownloadFailureKind.RESOURCE_UNAVAILABLE,
+            http_status=404,
+        )
+        with patch(
+            "src.utils.draft_downloader.download_draft_with_result",
+            return_value=result,
+        ):
+            msg = VideoGenTaskManager()._download_draft(_task())
+        assert msg == "草稿下载失败: 草稿或素材不存在/URL无效 (HTTP 404)"
+
+    @patch("src.utils.video_task_manager.sys.platform", "win32")
+    def test_network_retry_exhausted_message(self) -> None:
+        result = dd.DraftDownloadResult(
+            ok=False,
+            kind=dd.DraftDownloadFailureKind.NETWORK_RETRY_EXHAUSTED,
+        )
+        with patch(
+            "src.utils.draft_downloader.download_draft_with_result",
+            return_value=result,
+        ):
+            msg = VideoGenTaskManager()._download_draft(_task())
+        assert msg == "草稿下载失败: 网络不稳定，已多次重试仍失败，请稍后重试"
+
+    @patch("src.utils.video_task_manager.sys.platform", "win32")
+    def test_success_returns_empty(self) -> None:
+        with patch(
+            "src.utils.draft_downloader.download_draft_with_result",
+            return_value=dd.DraftDownloadResult(ok=True),
+        ):
+            assert VideoGenTaskManager()._download_draft(_task()) == ""
+
+    @patch("src.utils.video_task_manager.sys.platform", "win32")
+    @patch.object(VideoGenTaskManager, "_assign_export_outfile")
+    def test_phase_propagates_classified_message(self, m_out) -> None:
+        fail_msg = "草稿下载失败: 网络不稳定，已多次重试仍失败，请稍后重试"
+        with patch.object(
+            VideoGenTaskManager, "_download_draft", return_value=fail_msg
+        ):
+            out = VideoGenTaskManager()._phase_download_and_prepare(_task())
+        assert out == fail_msg