diff --git a/mars/services/task/analyzer/analyzer.py b/mars/services/task/analyzer/analyzer.py
index e70390e157..95b694ae86 100644
--- a/mars/services/task/analyzer/analyzer.py
+++ b/mars/services/task/analyzer/analyzer.py
@@ -128,6 +128,7 @@ def __init__(
         if graph_assigner_cls is None:
             graph_assigner_cls = GraphAssigner
         self._graph_assigner_cls = graph_assigner_cls
+        self._chunk_to_copied = dict()
         self._logic_key_generator = LogicKeyGenerator()
 
     @classmethod
@@ -226,6 +227,7 @@ def _gen_subtask_info(
         result_chunks_set = set()
         chunk_graph = ChunkGraph(result_chunks)
         out_of_scope_chunks = []
+        chunk_to_copied = self._chunk_to_copied
         update_meta_chunks = []
         # subtask properties
         band = None
@@ -271,11 +273,13 @@ def _gen_subtask_info(
                 chunk_priority = chunk.op.priority
             # process input chunks
             inp_chunks = []
+            input_changed = False
             build_fetch_index_to_chunks = dict()
             for i, inp_chunk in enumerate(chunk.inputs):
                 if inp_chunk in chunks_set:
-                    inp_chunks.append(inp_chunk)
+                    inp_chunks.append(chunk_to_copied[inp_chunk])
                 else:
+                    input_changed = True
                     build_fetch_index_to_chunks[i] = inp_chunk
                     inp_chunks.append(None)
                     if not isinstance(inp_chunk.op, Fetch):
@@ -285,14 +289,31 @@ def _gen_subtask_info(
             )
             for i, fetch_chunk in zip(build_fetch_index_to_chunks, fetch_chunks):
                 inp_chunks[i] = fetch_chunk
-            for out_chunk in chunk.op.outputs:
+
+            if input_changed:
+                copied_op = chunk.op.copy()
+                copied_op._key = chunk.op.key
+                out_chunks = [
+                    c.data
+                    for c in copied_op.new_chunks(
+                        inp_chunks, kws=[c.params.copy() for c in chunk.op.outputs]
+                    )
+                ]
+            else:
+                out_chunks = chunk.op.outputs
                 # Note: `dtypes`, `index_value`, and `columns_value` are lazily
                 # initialized, so we should call property `params` to initialize
                 # these fields.
-                out_chunk.params
-                processed.add(out_chunk)
+                [o.params for o in out_chunks]
+
+            for src_chunk, out_chunk in zip(chunk.op.outputs, out_chunks):
+                processed.add(src_chunk)
+                out_chunk._key = src_chunk.key
                 chunk_graph.add_node(out_chunk)
-                if out_chunk in self._final_result_chunks_set:
+                # cannot be copied twice
+                assert src_chunk not in chunk_to_copied
+                chunk_to_copied[src_chunk] = out_chunk
+                if src_chunk in self._final_result_chunks_set:
                     if out_chunk not in result_chunks_set:
                         # add to result chunks
                         result_chunks.append(out_chunk)
@@ -320,12 +341,18 @@ def _gen_subtask_info(
         if out_of_scope_chunks:
             inp_subtasks = []
             for out_of_scope_chunk in out_of_scope_chunks:
+                copied_out_of_scope_chunk = chunk_to_copied[out_of_scope_chunk]
                 inp_subtask = chunk_to_subtask[out_of_scope_chunk]
-                if out_of_scope_chunk not in inp_subtask.chunk_graph.result_chunks:
+                if (
+                    copied_out_of_scope_chunk
+                    not in inp_subtask.chunk_graph.result_chunks
+                ):
                     # make sure the chunk that out of scope
                     # is in the input subtask's results,
                     # or the meta may be lost
-                    inp_subtask.chunk_graph.result_chunks.append(out_of_scope_chunk)
+                    inp_subtask.chunk_graph.result_chunks.append(
+                        copied_out_of_scope_chunk
+                    )
                 inp_subtasks.append(inp_subtask)
             depth = max(st.priority[0] for st in inp_subtasks) + 1
         else:
@@ -383,9 +410,10 @@ def _gen_map_reduce_info(
             # record analyzer map reduce id for mapper op
             # copied chunk exists because map chunk must have
             # been processed before shuffle proxy
-            if not hasattr(map_chunk, "extra_params"):  # pragma: no cover
-                map_chunk.extra_params = dict()
-            map_chunk.extra_params["analyzer_map_reduce_id"] = map_reduce_id
+            copied_map_chunk = self._chunk_to_copied[map_chunk]
+            if not hasattr(copied_map_chunk, "extra_params"):  # pragma: no cover
+                copied_map_chunk.extra_params = dict()
+            copied_map_chunk.extra_params["analyzer_map_reduce_id"] = map_reduce_id
         reducer_bands = [assign_results[r.outputs[0]] for r in reducer_ops]
         map_reduce_info = MapReduceInfo(
             map_reduce_id=map_reduce_id,
diff --git a/mars/services/task/supervisor/tests/task_preprocessor.py b/mars/services/task/supervisor/tests/task_preprocessor.py
index 496c0037e4..89ea51faa3 100644
--- a/mars/services/task/supervisor/tests/task_preprocessor.py
+++ b/mars/services/task/supervisor/tests/task_preprocessor.py
@@ -180,7 +180,11 @@ def analyze(
             map_reduce_id_to_infos=self.map_reduce_id_to_infos,
         )
         subtask_graph = analyzer.gen_subtask_graph()
-        results = set(c for c in chunk_graph.results if not isinstance(c.op, Fetch))
+        results = set(
+            analyzer._chunk_to_copied[c]
+            for c in chunk_graph.results
+            if not isinstance(c.op, Fetch)
+        )
         for subtask in subtask_graph:
             if subtask.extra_config is None:
                 subtask.extra_config = dict()