diff --git a/CHANGES b/CHANGES
index 5e30dc7ed3d..eb041082ff8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -19,6 +19,7 @@ Bugs fixed
 * #8372: autodoc: autoclass directive became slower than Sphinx-3.2
 * #7727: autosummary: raise PycodeError when documenting python package
   without __init__.py
+* #8350: autosummary: autosummary_mock_imports causes slow down builds
 * #8364: C, properly initialize attributes in empty symbols.
 * #8399: i18n: Put system locale path after the paths specified by configuration
 
diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index f2cd8070bb4..9f5bf785e09 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -122,7 +122,11 @@ def getargspec(func: Callable) -> Any:
 def unwrap(obj: Any) -> Any:
     """Get an original object from wrapped object (wrapped functions)."""
     try:
-        return inspect.unwrap(obj)
+        if hasattr(obj, '__sphinx_mock__'):
+            # Skip unwrapping mock object to avoid RecursionError
+            return obj
+        else:
+            return inspect.unwrap(obj)
     except ValueError:
         # might be a mock object
         return obj