diff --git a/fastdeploy/cache_manager/prefix_cache_manager.py b/fastdeploy/cache_manager/prefix_cache_manager.py
index e12e47d3fd0..c41a6109029 100644
--- a/fastdeploy/cache_manager/prefix_cache_manager.py
+++ b/fastdeploy/cache_manager/prefix_cache_manager.py
@@ -731,6 +731,8 @@ def update_cache_blocks(self, task, block_size, num_computed_tokens):
             req_id = task.request_id
             last_node, num_cached_tokens = self.req_to_radix_tree_info[req_id]
             can_cache_computed_tokens = num_computed_tokens - num_computed_tokens % block_size
+            if can_cache_computed_tokens <= num_cached_tokens:
+                return
             if req_id in self.leaf_req_map[last_node]:  # delete old leaf record, update later
                 self.leaf_req_map[last_node].remove(req_id)
             logger.debug(