diff --git a/afd_plugin/model_executor/models/model_utils.py b/afd_plugin/model_executor/models/model_utils.py
index 4edc7273..ecfb1568 100644
--- a/afd_plugin/model_executor/models/model_utils.py
+++ b/afd_plugin/model_executor/models/model_utils.py
@@ -4,7 +4,7 @@
 
 from __future__ import annotations
 
-from copy import copy
+from copy import deepcopy
 from typing import TYPE_CHECKING
 
 from afd_plugin import _DEEPSEEK_MODEL_REGISTRATIONS
@@ -18,8 +18,11 @@ def get_afd_model_config(model_config: ModelConfig) -> ModelConfig:
 
     for model_arch in model_config.hf_config.architectures:
         if model_arch in _DEEPSEEK_MODEL_REGISTRATIONS:
-            afd_model_config = copy(model_config)
-            afd_model_config.hf_config = copy(model_config.hf_config)
+            # deepcopy preserves aliasing within the copied object graph, so
+            # the pure-text identity hf_text_config is hf_config is retained
+            # automatically. vLLM Ascend uses that identity to distinguish
+            # text models from multimodal models.
+            afd_model_config = deepcopy(model_config)
             afd_model_config.hf_config.architectures = [f"AFD{model_arch}"]
             return afd_model_config
     return model_config
diff --git a/tests/unit/package/test_package.py b/tests/unit/package/test_package.py
index 6a379557..6966bc18 100644
--- a/tests/unit/package/test_package.py
+++ b/tests/unit/package/test_package.py
@@ -50,18 +50,40 @@ def test_afd_model_config_uses_private_architecture_copy():
     pytest.importorskip("vllm")
     from afd_plugin.model_executor.models.model_utils import get_afd_model_config
 
+    hf_config = SimpleNamespace(architectures=["DeepseekV2ForCausalLM"])
     model_config = SimpleNamespace(
-        hf_config=SimpleNamespace(architectures=["DeepseekV2ForCausalLM"]),
+        hf_config=hf_config,
+        hf_text_config=hf_config,
     )
 
     afd_model_config = get_afd_model_config(model_config)
 
     assert afd_model_config is not model_config
     assert afd_model_config.hf_config is not model_config.hf_config
+    assert afd_model_config.hf_text_config is afd_model_config.hf_config
     assert afd_model_config.hf_config.architectures == ["AFDDeepseekV2ForCausalLM"]
     assert model_config.hf_config.architectures == ["DeepseekV2ForCausalLM"]
 
 
+def test_afd_model_config_preserves_nested_text_config():
+    pytest.importorskip("vllm")
+    from afd_plugin.model_executor.models.model_utils import get_afd_model_config
+
+    hf_text_config = SimpleNamespace()
+    model_config = SimpleNamespace(
+        hf_config=SimpleNamespace(architectures=["DeepseekV2ForCausalLM"]),
+        hf_text_config=hf_text_config,
+    )
+
+    afd_model_config = get_afd_model_config(model_config)
+
+    # deepcopy privatizes the whole graph; a genuinely distinct nested
+    # hf_text_config stays distinct from hf_config.
+    assert afd_model_config.hf_config is not model_config.hf_config
+    assert afd_model_config.hf_text_config is not hf_text_config
+    assert afd_model_config.hf_text_config is not afd_model_config.hf_config
+
+
 def test_entry_point_is_registered():
     entry_points = importlib.metadata.entry_points(group="vllm.general_plugins")
     matches = [ep for ep in entry_points if ep.name == "afd"]