diff --git a/app/harness/tree_nodes.py b/app/harness/tree_nodes.py
index 39f6ccb..5db245d 100644
--- a/app/harness/tree_nodes.py
+++ b/app/harness/tree_nodes.py
@@ -30,7 +30,7 @@ def load_tree_nodes(store_dir: Path, video_id: str) -> dict[str, Any]:
 
     异常:
         FileNotFoundError: tree.json 不存在（沿用 factory.py fail-loud 先例）。
-        ValueError: 树无有效 roots、节点缺 id、或展平后 nodes 为空。
+        ValueError: roots 非 list 或为空、节点缺 id、或节点既无 time_range 又无 timestamp。
 
     关键实现:
         level 由遍历深度赋值（root=1/child=2/孙=3），不解析 node_id——node_id 累积式
@@ -54,7 +54,11 @@ def load_tree_nodes(store_dir: Path, video_id: str) -> dict[str, Any]:
         time_range = node.get("time_range")
         if time_range is None:
             ts = node.get("timestamp")
-            time_range = [ts, ts] if ts is not None else [0, 0]
+            if ts is None:
+                raise ValueError(
+                    f"节点既无 time_range 又无 timestamp（树损坏）: {node_id} in {tree_path}"
+                )
+            time_range = [ts, ts]
         nodes[node_id] = {
             "card": node.get("card", {}),
             "level": level,
diff --git a/tests/unit/test_tree_nodes.py b/tests/unit/test_tree_nodes.py
index 72cb7e9..89a9091 100644
--- a/tests/unit/test_tree_nodes.py
+++ b/tests/unit/test_tree_nodes.py
@@ -7,7 +7,7 @@ import pytest
 
 from app.harness.tree_nodes import load_tree_data_for_videos, load_tree_nodes
 
-_STORE = Path("store")
+_STORE = Path(__file__).resolve().parents[2] / "store"
 _VID = "0RxMZBLeqRI"  # 真实样本，111 节点
 
 
@@ -68,6 +68,16 @@ def test_roots_not_list_raises_value_error(tmp_path):
         load_tree_nodes(tmp_path, "vX")
 
 
+def test_node_without_time_info_raises_value_error(tmp_path):
+    vdir = tmp_path / "videos" / "vX"
+    vdir.mkdir(parents=True)
+    (vdir / "tree.json").write_text(
+        json.dumps({"roots": [{"id": "n1", "card": {}}]}), encoding="utf-8"
+    )
+    with pytest.raises(ValueError):
+        load_tree_nodes(tmp_path, "vX")
+
+
 def test_load_for_videos_dedups():
     data = load_tree_data_for_videos(_STORE, [_VID, _VID])
     assert set(data.keys()) == {_VID}