diff --git a/llmc/compression/token_reduction/mustdrop.py b/llmc/compression/token_reduction/mustdrop.py
index 7f72f800..ab00fe53 100644
--- a/llmc/compression/token_reduction/mustdrop.py
+++ b/llmc/compression/token_reduction/mustdrop.py
@@ -15,6 +15,7 @@ def __init__(self, config, model, blocks):
         self.register_reduction_modules()
 
     def add_sparse_config(self):
+        self.pruning_loc = self.special_config['pruning_loc']
         self.pruning_paras = self.special_config
 
     def register_reduction_modules(self):
@@ -30,6 +31,7 @@ def conditional_pooling(
             feat: torch.Tensor,
             threshold: float,
             window_size: Tuple[int, int],
+            fix_r: int = 0,
         ) -> Tuple[Callable, Callable]:
 
             with torch.no_grad():
@@ -91,7 +93,8 @@ def conditional_pooling(
                 node_mean = node_mean.repeat(1, n_H)
                 r = torch.ge(similarity_map, node_mean).sum(dim=1).min()
                 # -------------#
-
+                if fix_r != 0:
+                    r = fix_r
                 #   get top k similar super patches
                 _, sim_super_patch_idxs = similarity_map.topk(r, dim=-1)
 
@@ -184,17 +187,20 @@ def merge_wavg(
 
             return x, size
 
-        def spatial_merge_hook(module, args, kwargs, pruning_paras):
+        def spatial_merge_hook(module, args, kwargs, layer_outs, pruning_paras):
             spatial_threshold = pruning_paras['spatial_threshold']
             window_size = pruning_paras['window_size']
-            hidden_states = args[0]
-            merge = conditional_pooling(hidden_states, spatial_threshold, window_size)
+            hidden_states = layer_outs[0]
+            fix_r = 0
+            if pruning_paras.get('retained_tokens', None) is not None:
+                retained_tokens = pruning_paras['retained_tokens']
+                fix_r = (pruning_paras['vision_token_length'] - retained_tokens) \
+                    // (window_size[0] * window_size[1] - 1)
+            merge = conditional_pooling(hidden_states, spatial_threshold, window_size, fix_r)
             hidden_states, size = merge_wavg(merge, hidden_states, None)
-            return (hidden_states,) + args[1:], kwargs
+            return (hidden_states,)
 
-        self.model.set_modality('vision')
-        self.model.find_blocks()
-        self.model.blocks[1].register_forward_pre_hook(
+        self.blocks[self.pruning_loc - 1].register_forward_hook(
             functools.partial(spatial_merge_hook, pruning_paras=self.pruning_paras),
             with_kwargs=True,
         )