diff --git a/cobol_testgen/blackbox.py b/cobol_testgen/blackbox.py
index 22d0cb1..40ab52c 100644
--- a/cobol_testgen/blackbox.py
+++ b/cobol_testgen/blackbox.py
@@ -45,10 +45,14 @@ def _resolve_fd(bb_key, fd_aliases: dict):
     for fd_name, aliases in fd_aliases.items():
         if nk in aliases:
             return fd_name
-    for fd_name, aliases in fd_aliases.items():
-        for a in aliases:
-            if a and (nk.startswith(a) or a.startswith(nk)):
-                return fd_name
+    matches = [
+        fd_name for fd_name, aliases in fd_aliases.items()
+        if any(a and (nk.startswith(a) or a.startswith(nk)) for a in aliases)
+    ]
+    if len(matches) == 1:
+        return matches[0]
+    if len(matches) > 1:
+        logger.warning(f"黑盒 FD '{bb_key}' 匹配到多个: {matches}，跳过")
     return None
 
 
@@ -70,10 +74,7 @@ def _iter_group_files(path: Path) -> list[Path]:
     files = sorted(p.glob('*_g*.json'))
     if files:
         return files
-    bb = p / 'black_box'
-    if bb.is_dir():
-        return sorted(bb.rglob('*_g*.json'))
-    return []
+    return sorted(p.rglob('*_g*.json'))
 
 
 def _group_label(json_path: Path) -> str:
@@ -84,6 +85,8 @@ def _group_label(json_path: Path) -> str:
 
 
 def _map_record(raw, fd_aliases, field_map, jf: Path) -> dict:
+    if not isinstance(raw, dict):
+        return {}
     inp = raw.get('input')
     if not isinstance(inp, dict):
         return {}
@@ -119,6 +122,9 @@ def load_black_box_groups(path, fd_fields: dict, select_info: dict,
         except Exception as e:  # noqa: BLE001
             logger.warning(f"黑盒 JSON 解析失败 {jf}: {e}")
             continue
+        if not isinstance(obj, dict):
+            logger.warning(f"黑盒 JSON 顶层非对象，跳过: {jf}")
+            continue
         label = _group_label(jf)
         records = []
         for raw in obj.get('records', []) or []:
diff --git a/tests/cobol_testgen/test_blackbox.py b/tests/cobol_testgen/test_blackbox.py
index c54d852..d5082a4 100644
--- a/tests/cobol_testgen/test_blackbox.py
+++ b/tests/cobol_testgen/test_blackbox.py
@@ -21,7 +21,7 @@ def _write_group(tmp, name, payload):
 
 def test_norm_name():
     assert norm_name("R01-APPL-ID") == "R01APPLID"
-    assert norm_name("R01APPL-ID") == "R01APPLID"
+    assert norm_name("R01APPLID") == "R01APPLID"
     assert norm_name("r01_appl_id") == "R01APPLID"
 
 
@@ -75,3 +75,58 @@ def test_load_groups_skips_unmatched_and_empty():
         })
         groups = load_black_box_groups(tmp, fd_fields, select_info, data_fields)
         assert groups == []
+
+
+def test_load_groups_fd_prefix_variant():
+    fd_fields = {"R01INNFIL": ["R01APPL-ID"]}
+    select_info = {"R01INNFIL": {"assign": "ZAN04R01"}}
+    data_fields = [{"name": "R01APPL-ID", "pic": "X(8)"}]
+    with tempfile.TemporaryDirectory() as tmp:
+        _write_group(tmp, "ZAN04MAT_g1", {
+            "program": "ZAN04MAT",
+            "records": [{"input": {"R01": {"R01-APPL-ID": "C0000003"}}}],
+        })
+        groups = load_black_box_groups(tmp, fd_fields, select_info, data_fields)
+        assert groups[0].records[0]["R01APPL-ID"] == "C0000003"
+
+
+def test_load_groups_ambiguous_prefix_skipped():
+    fd_fields = {"R01INNFIL": ["R01APPL-ID"], "R01OUTFIL": ["R01APPL-ID"]}
+    select_info = {"R01INNFIL": {"assign": "ZAN04R01"},
+                   "R01OUTFIL": {"assign": "ZAN04W01"}}
+    data_fields = [{"name": "R01APPL-ID", "pic": "X(8)"}]
+    with tempfile.TemporaryDirectory() as tmp:
+        _write_group(tmp, "ZAN04MAT_g1", {
+            "program": "ZAN04MAT",
+            "records": [{"input": {"R01": {"R01-APPL-ID": "D0000004"}}}],
+        })
+        groups = load_black_box_groups(tmp, fd_fields, select_info, data_fields)
+        assert groups == []
+
+
+def test_load_groups_accepts_black_box_dir_directly():
+    fd_fields = {"R01INNFIL": ["R01APPL-ID"]}
+    select_info = {"R01INNFIL": {"assign": "ZAN04R01"}}
+    data_fields = [{"name": "R01APPL-ID", "pic": "X(8)"}]
+    with tempfile.TemporaryDirectory() as tmp:
+        _write_group(tmp, "ZAN04MAT_g1", {
+            "program": "ZAN04MAT",
+            "records": [{"input": {"ZAN04R01": {"R01APPL-ID": "E0000005"}}}],
+        })
+        groups = load_black_box_groups(Path(tmp) / "black_box", fd_fields,
+                                       select_info, data_fields)
+        assert len(groups) == 1
+
+
+def test_load_groups_skips_non_dict_records():
+    fd_fields = {"R01INNFIL": ["R01APPL-ID"]}
+    select_info = {"R01INNFIL": {"assign": "ZAN04R01"}}
+    data_fields = [{"name": "R01APPL-ID", "pic": "X(8)"}]
+    with tempfile.TemporaryDirectory() as tmp:
+        _write_group(tmp, "ZAN04MAT_g1", {
+            "program": "ZAN04MAT",
+            "records": ["not-a-dict",
+                        {"input": {"ZAN04R01": {"R01APPL-ID": "F0000006"}}}],
+        })
+        groups = load_black_box_groups(tmp, fd_fields, select_info, data_fields)
+        assert groups[0].records[0]["R01APPL-ID"] == "F0000006"