diff --git a/src/memos/mem_reader/multi_modal_struct.py b/src/memos/mem_reader/multi_modal_struct.py
index ed139f95..219b24e5 100644
--- a/src/memos/mem_reader/multi_modal_struct.py
+++ b/src/memos/mem_reader/multi_modal_struct.py
@@ -570,6 +570,9 @@ def _process_transfer_multi_modal_data(
             "session_id": raw_node.metadata.session_id,
             **(raw_node.metadata.info or {}),
         }
+        # Explicitly pass file_ids to preserve file association during transfer
+        if hasattr(raw_node.metadata, "file_ids") and raw_node.metadata.file_ids:
+            info["file_ids"] = raw_node.metadata.file_ids
 
         fine_memory_items = []
         # Part A: call llm
diff --git a/src/memos/mem_reader/read_multi_modal/file_content_parser.py b/src/memos/mem_reader/read_multi_modal/file_content_parser.py
index cce99e76..4561c10d 100644
--- a/src/memos/mem_reader/read_multi_modal/file_content_parser.py
+++ b/src/memos/mem_reader/read_multi_modal/file_content_parser.py
@@ -179,6 +179,11 @@ def create_source(
                 "doc_path": file_info.get("filename") or file_info.get("file_id", ""),
                 "content": chunk_content if chunk_content else file_info.get("file_data", ""),
             }
+            # Persist file_id in source_dict if available
+            file_id = file_info.get("file_id")
+            if file_id:
+                source_dict["file_id"] = file_id
+
             # Add chunk ordering information if provided
             if chunk_index is not None:
                 source_dict["chunk_index"] = chunk_index
@@ -199,13 +204,18 @@ def rebuild_from_source(
         source: SourceMessage,
     ) -> File:
         """Rebuild file content part from SourceMessage."""
+        file_data = {
+            "filename": source.doc_path or "",
+            "file_data": source.content or "",
+        }
+        # Restore file_id if present in source
+        if hasattr(source, "file_id") and source.file_id:
+            file_data["file_id"] = source.file_id
+
         # Rebuild from source fields
         return {
             "type": "file",
-            "file": {
-                "filename": source.doc_path or "",
-                "file_data": source.content or "",
-            },
+            "file": file_data,
         }
 
     def _parse_file(self, file_info: dict[str, Any]) -> str:
@@ -527,7 +537,18 @@ def parse_fine(
         session_id = info_.pop("session_id", "")
         if file_id:
             info_["file_id"] = file_id
-        file_ids = [file_id] if file_id else []
+
+        file_ids = []
+        if file_id:
+            file_ids = [file_id]
+        elif info.get("file_id"):
+            file_ids = [info.get("file_id")]
+            info_["file_id"] = info.get("file_id")
+        elif info.get("file_ids"):
+            # Support retrieve from file_ids list
+            file_ids = info.get("file_ids")
+            if len(file_ids) > 0:
+                info_["file_id"] = file_ids[0]
         # For file content parts, default to LongTermMemory
         memory_type = "LongTermMemory"