diff --git a/src/memos/configs/mem_reader.py b/src/memos/configs/mem_reader.py
index f5e1aaba0..a0b72efd1 100644
--- a/src/memos/configs/mem_reader.py
+++ b/src/memos/configs/mem_reader.py
@@ -44,7 +44,6 @@ def parse_datetime(cls, value):
 class SimpleStructMemReaderConfig(BaseMemReaderConfig):
     """SimpleStruct MemReader configuration class."""
 
-    # Allow passing additional fields without raising validation errors
     model_config = ConfigDict(extra="allow", strict=True)
 
 
@@ -61,6 +60,8 @@ class MultiModalStructMemReaderConfig(BaseMemReaderConfig):
 class StrategyStructMemReaderConfig(BaseMemReaderConfig):
     """StrategyStruct MemReader configuration class."""
 
+    model_config = ConfigDict(extra="allow", strict=True)
+
 
 class MemReaderConfigFactory(BaseConfig):
     """Factory class for creating MemReader configurations."""
diff --git a/src/memos/mem_reader/multi_modal_struct.py b/src/memos/mem_reader/multi_modal_struct.py
index 7da013b48..0cb4e1542 100644
--- a/src/memos/mem_reader/multi_modal_struct.py
+++ b/src/memos/mem_reader/multi_modal_struct.py
@@ -8,7 +8,7 @@
 from memos.configs.mem_reader import MultiModalStructMemReaderConfig
 from memos.context.context import ContextThreadPoolExecutor
 from memos.mem_reader.read_multi_modal import MultiModalParser, detect_lang
-from memos.mem_reader.simple_struct import SimpleStructMemReader
+from memos.mem_reader.simple_struct import PROMPT_DICT, SimpleStructMemReader
 from memos.memories.textual.item import TextualMemoryItem
 from memos.templates.tool_mem_prompts import TOOL_TRAJECTORY_PROMPT_EN, TOOL_TRAJECTORY_PROMPT_ZH
 from memos.types import MessagesType
@@ -248,6 +248,104 @@ def _build_window_from_items(
 
         return aggregated_item
 
+    def _get_llm_response(
+        self,
+        mem_str: str,
+        custom_tags: list[str] | None = None,
+        sources: list | None = None,
+        prompt_type: str = "chat",
+    ) -> dict:
+        """
+        Override parent method to improve language detection by using actual text content
+        from sources instead of JSON-structured memory string.
+
+        Args:
+            mem_str: Memory string (may contain JSON structures)
+            custom_tags: Optional custom tags
+            sources: Optional list of SourceMessage objects to extract text content from
+            prompt_type: Type of prompt to use ("chat" or "doc")
+
+        Returns:
+            LLM response dictionary
+        """
+        # Try to extract actual text content from sources for better language detection
+        text_for_lang_detection = mem_str
+        if sources:
+            source_texts = []
+            for source in sources:
+                if hasattr(source, "content") and source.content:
+                    source_texts.append(source.content)
+                elif isinstance(source, dict) and source.get("content"):
+                    source_texts.append(source.get("content"))
+
+            # If we have text content from sources, use it for language detection
+            if source_texts:
+                text_for_lang_detection = " ".join(source_texts)
+
+        # Use the extracted text for language detection
+        lang = detect_lang(text_for_lang_detection)
+
+        # Select prompt template based on prompt_type
+        if prompt_type == "doc":
+            template = PROMPT_DICT["doc"][lang]
+            examples = ""  # doc prompts don't have examples
+            prompt = template.replace("{chunk_text}", mem_str)
+        else:
+            template = PROMPT_DICT["chat"][lang]
+            examples = PROMPT_DICT["chat"][f"{lang}_example"]
+            prompt = template.replace("${conversation}", mem_str)
+
+        custom_tags_prompt = (
+            PROMPT_DICT["custom_tags"][lang].replace("{custom_tags}", str(custom_tags))
+            if custom_tags
+            else ""
+        )
+
+        # Replace custom_tags_prompt placeholder (different for doc vs chat)
+        if prompt_type == "doc":
+            prompt = prompt.replace("{custom_tags_prompt}", custom_tags_prompt)
+        else:
+            prompt = prompt.replace("${custom_tags_prompt}", custom_tags_prompt)
+
+        if self.config.remove_prompt_example and examples:
+            prompt = prompt.replace(examples, "")
+        messages = [{"role": "user", "content": prompt}]
+        try:
+            response_text = self.llm.generate(messages)
+            response_json = self.parse_json_result(response_text)
+        except Exception as e:
+            logger.error(f"[LLM] Exception during chat generation: {e}")
+            response_json = {
+                "memory list": [
+                    {
+                        "key": mem_str[:10],
+                        "memory_type": "UserMemory",
+                        "value": mem_str,
+                        "tags": [],
+                    }
+                ],
+                "summary": mem_str,
+            }
+        return response_json
+
+    def _determine_prompt_type(self, sources: list) -> str:
+        """
+        Determine prompt type based on sources.
+        """
+        if not sources:
+            return "chat"
+        prompt_type = "doc"
+        for source in sources:
+            source_role = None
+            if hasattr(source, "role"):
+                source_role = source.role
+            elif isinstance(source, dict):
+                source_role = source.get("role")
+            if source_role in {"user", "assistant", "system", "tool"}:
+                prompt_type = "chat"
+
+        return prompt_type
+
     def _process_string_fine(
         self,
         fast_memory_items: list[TextualMemoryItem],
@@ -270,8 +368,12 @@ def _process_string_fine(
             sources = fast_item.metadata.sources or []
             if not isinstance(sources, list):
                 sources = [sources]
+
+            # Determine prompt type based on sources
+            prompt_type = self._determine_prompt_type(sources)
+
             try:
-                resp = self._get_llm_response(mem_str, custom_tags)
+                resp = self._get_llm_response(mem_str, custom_tags, sources, prompt_type)
             except Exception as e:
                 logger.error(f"[MultiModalFine] Error calling LLM: {e}")
                 continue