diff --git a/app/utils/milvus_utils.py b/app/utils/milvus_utils.py
index 56d36cf..85b7df1 100644
--- a/app/utils/milvus_utils.py
+++ b/app/utils/milvus_utils.py
@@ -43,8 +43,8 @@ class MilvusService:
       vector_store=vector_store,
       embed_model=self.embeddings,
     )
-    from llama_index.core.node_parser import SimpleNodeParser
-    parser = SimpleNodeParser()
+    from llama_index.core.node_parser import HierarchicalNodeParser
+    parser = HierarchicalNodeParser.from_defaults(chunk_sizes=[2048, 512, 128])
     nodes = parser.get_nodes_from_documents(documents)
     await vector_index.ainsert_nodes(nodes)
     return vector_index