diff --git a/Tools/ModelTranslator/rizom_unwrap.py b/Tools/ModelTranslator/rizom_unwrap.py
index 8bcdcf14..1a4b694a 100644
--- a/Tools/ModelTranslator/rizom_unwrap.py
+++ b/Tools/ModelTranslator/rizom_unwrap.py
@@ -43,9 +43,14 @@ def registry_rizom_path():
 
 
 def find_rizomuv(cli_arg=None, use_registry=True, default=DEFAULT_RIZOM):
-    """返回第一个真实存在的 rizomuv.exe；都不存在抛 RizomError。"""
+    """返回第一个真实存在的 rizomuv.exe；都不存在抛 RizomError。
+    显式指定 cli_arg 时独占生效：路径无效直接报错，不回落其它候选。"""
+    if cli_arg:
+        if os.path.isfile(cli_arg):
+            return cli_arg
+        raise RizomError("指定的 rizomuv.exe 不存在：%s" % cli_arg)
     reg = registry_rizom_path() if use_registry else None
-    cands = candidate_paths(cli_arg, os.environ.get("RIZOMUV_EXE"), reg, default)
+    cands = candidate_paths(None, os.environ.get("RIZOMUV_EXE"), reg, default)
     for p in cands:
         if os.path.isfile(p):
             return p
diff --git a/Tools/ModelTranslator/tests/test_rizom_unwrap.py b/Tools/ModelTranslator/tests/test_rizom_unwrap.py
index d3769b97..67cf70ab 100644
--- a/Tools/ModelTranslator/tests/test_rizom_unwrap.py
+++ b/Tools/ModelTranslator/tests/test_rizom_unwrap.py
@@ -29,6 +29,12 @@ class TestFindRizomuv(unittest.TestCase):
                 ru.find_rizomuv("Z:/no/such/rizomuv.exe", use_registry=False,
                                 default="Z:/no/default.exe")
 
+    def test_explicit_cli_path_is_exclusive(self):
+        # 显式指定的路径不存在必须直接抛错，不得回落默认安装
+        with self.assertRaises(ru.RizomError) as cm:
+            ru.find_rizomuv("Z:/explicit/bad.exe")
+        self.assertIn("Z:/explicit/bad.exe", str(cm.exception))
+
     def test_registry_value_is_real_exe_if_present(self):
         p = ru.registry_rizom_path()
         if p is None: