diff --git a/mmrazor/models/mutables/mutable_channel/mutable_channel_container.py b/mmrazor/models/mutables/mutable_channel/mutable_channel_container.py
index 5706d0750..f9eeecc32 100644
--- a/mmrazor/models/mutables/mutable_channel/mutable_channel_container.py
+++ b/mmrazor/models/mutables/mutable_channel/mutable_channel_container.py
@@ -115,7 +115,7 @@ def _fill_unregistered_range(self):
         for start, end in copy.copy(self.mutable_channels):
             if last_end < start:
                 self.register_mutable(
-                    SimpleMutableChannel(last_end - start), last_end, start)
+                    SimpleMutableChannel(start - last_end), last_end, start)
             last_end = end
         if last_end < self.num_channels:
             self.register_mutable(