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diff --git a/backend/app/api/endpoints/__pycache__/rag.cpython-312.pyc b/backend/app/api/endpoints/__pycache__/rag.cpython-312.pyc
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diff --git a/backend/app/api/endpoints/__pycache__/tasks.cpython-312.pyc b/backend/app/api/endpoints/__pycache__/tasks.cpython-312.pyc
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diff --git a/backend/app/api/endpoints/__pycache__/templates.cpython-312.pyc b/backend/app/api/endpoints/__pycache__/templates.cpython-312.pyc
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diff --git a/backend/app/config.py b/backend/app/config.py
index 5e0e871..879555d 100644
--- a/backend/app/config.py
+++ b/backend/app/config.py
@@ -45,11 +45,20 @@ class Settings(BaseSettings):
 
     @property
     def mysql_url(self) -> str:
-        """生成MySQL连接URL"""
+        """生成MySQL连接URL (同步)"""
         return (
             f"mysql+pymysql://{self.MYSQL_USER}:{self.MYSQL_PASSWORD}"
             f"@{self.MYSQL_HOST}:{self.MYSQL_PORT}/{self.MYSQL_DATABASE}"
             f"?charset={self.MYSQL_CHARSET}"
         )
 
+    @property
+    def async_mysql_url(self) -> str:
+        """生成MySQL连接URL (异步)"""
+        return (
+            f"mysql+aiomysql://{self.MYSQL_USER}:{self.MYSQL_PASSWORD}"
+            f"@{self.MYSQL_HOST}:{self.MYSQL_PORT}/{self.MYSQL_DATABASE}"
+            f"?charset={self.MYSQL_CHARSET}"
+        )
+
 settings = Settings()
\ No newline at end of file
diff --git a/backend/app/core/database/__pycache__/mongodb.cpython-312.pyc b/backend/app/core/database/__pycache__/mongodb.cpython-312.pyc
new file mode 100644
index 0000000..479f37b
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diff --git a/backend/app/core/database/__pycache__/mysql.cpython-312.pyc b/backend/app/core/database/__pycache__/mysql.cpython-312.pyc
index 0f1ebba..0347b2c 100644
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diff --git a/backend/app/core/database/__pycache__/redis_db.cpython-312.pyc b/backend/app/core/database/__pycache__/redis_db.cpython-312.pyc
new file mode 100644
index 0000000..2a8d672
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diff --git a/backend/app/core/database/mysql.py b/backend/app/core/database/mysql.py
index 6e5b318..9ecfe9b 100644
--- a/backend/app/core/database/mysql.py
+++ b/backend/app/core/database/mysql.py
@@ -37,7 +37,7 @@ class MySQLDB:
     def __init__(self):
         # 异步引擎 (用于 FastAPI 异步操作)
         self.async_engine = create_async_engine(
-            settings.mysql_url,
+            settings.async_mysql_url,
             echo=settings.DEBUG,  # SQL 日志
             pool_pre_ping=True,   # 连接前检测
             pool_size=10,
@@ -55,7 +55,7 @@ class MySQLDB:
 
         # 同步引擎 (用于 Celery 同步任务)
         self.sync_engine = create_engine(
-            settings.mysql_url.replace("mysql+pymysql", "mysql"),
+            settings.mysql_url,
             echo=settings.DEBUG,
             pool_pre_ping=True,
             pool_size=5,
diff --git a/backend/app/core/database/redis_db.py b/backend/app/core/database/redis_db.py
index 780a07b..83b21e9 100644
--- a/backend/app/core/database/redis_db.py
+++ b/backend/app/core/database/redis_db.py
@@ -6,7 +6,7 @@ Redis 数据库连接管理模块
 import json
 import logging
 from datetime import timedelta
-from typing import Any, Optional
+from typing import Any, Dict, Optional
 
 import redis.asyncio as redis
 
diff --git a/backend/app/services/__pycache__/excel_storage_service.cpython-312.pyc b/backend/app/services/__pycache__/excel_storage_service.cpython-312.pyc
new file mode 100644
index 0000000..91bd263
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diff --git a/backend/app/services/__pycache__/rag_service.cpython-312.pyc b/backend/app/services/__pycache__/rag_service.cpython-312.pyc
new file mode 100644
index 0000000..856ba0a
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diff --git a/backend/app/services/__pycache__/table_rag_service.cpython-312.pyc b/backend/app/services/__pycache__/table_rag_service.cpython-312.pyc
new file mode 100644
index 0000000..2239298
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diff --git a/backend/app/services/__pycache__/template_fill_service.cpython-312.pyc b/backend/app/services/__pycache__/template_fill_service.cpython-312.pyc
new file mode 100644
index 0000000..ea3101e
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diff --git a/backend/app/services/rag_service.py b/backend/app/services/rag_service.py
index 80f705a..65bdb40 100644
--- a/backend/app/services/rag_service.py
+++ b/backend/app/services/rag_service.py
@@ -1,48 +1,54 @@
 """
 RAG 服务模块 - 检索增强生成
 
-使用 LangChain + Faiss 实现向量检索
+使用 sentence-transformers + Faiss 实现向量检索
 """
+import json
 import logging
 import os
+import pickle
 from typing import Any, Dict, List, Optional
 
-from langchain.embeddings import HuggingFaceEmbeddings
-from langchain.schema import Document as LangchainDocument
-from langchain.vectorstores import FAISS
+import faiss
+import numpy as np
+from sentence_transformers import SentenceTransformer
 
 from app.config import settings
 
 logger = logging.getLogger(__name__)
 
 
+class SimpleDocument:
+    """简化文档对象"""
+    def __init__(self, page_content: str, metadata: Dict[str, Any]):
+        self.page_content = page_content
+        self.metadata = metadata
+
+
 class RAGService:
     """RAG 检索增强服务"""
 
     def __init__(self):
-        self.embeddings: Optional[HuggingFaceEmbeddings] = None
-        self.vector_store: Optional[FAISS] = None
+        self.embedding_model: Optional[SentenceTransformer] = None
+        self.index: Optional[faiss.Index] = None
+        self.documents: List[Dict[str, Any]] = []
+        self.doc_ids: List[str] = []
+        self._dimension: int = 0
         self._initialized = False
+        self._persist_dir = settings.FAISS_INDEX_DIR
 
     def _init_embeddings(self):
         """初始化嵌入模型"""
-        if self.embeddings is None:
-            self.embeddings = HuggingFaceEmbeddings(
-                model_name=settings.EMBEDDING_MODEL,
-                model_kwargs={'device': 'cpu'}
-            )
-            logger.info(f"RAG 嵌入模型初始化完成: {settings.EMBEDDING_MODEL}")
+        if self.embedding_model is None:
+            self.embedding_model = SentenceTransformer(settings.EMBEDDING_MODEL)
+            self._dimension = self.embedding_model.get_sentence_embedding_dimension()
+            logger.info(f"RAG 嵌入模型初始化完成: {settings.EMBEDDING_MODEL}, 维度: {self._dimension}")
 
     def _init_vector_store(self):
         """初始化向量存储"""
-        if self.vector_store is None:
+        if self.index is None:
             self._init_embeddings()
-            self.vector_store = FAISS(
-                embedding_function=self.embeddings,
-                index=None,  # 创建一个空索引
-                docstore={},
-                index_to_docstore_id={}
-            )
+            self.index = faiss.IndexIDMap(faiss.IndexFlatIP(self._dimension))
             logger.info("Faiss 向量存储初始化完成")
 
     async def initialize(self):
@@ -55,6 +61,12 @@ class RAGService:
             logger.error(f"RAG 服务初始化失败: {e}")
             raise
 
+    def _normalize_vectors(self, vectors: np.ndarray) -> np.ndarray:
+        """归一化向量"""
+        norms = np.linalg.norm(vectors, axis=1, keepdims=True)
+        norms = np.where(norms == 0, 1, norms)
+        return vectors / norms
+
     def index_field(
         self,
         table_name: str,
@@ -62,39 +74,20 @@ class RAGService:
         field_description: str,
         sample_values: Optional[List[str]] = None
     ):
-        """
-        将字段信息索引到向量数据库
-
-        Args:
-            table_name: 表名
-            field_name: 字段名
-            field_description: 字段语义描述
-            sample_values: 示例值
-        """
+        """将字段信息索引到向量数据库"""
         if not self._initialized:
             self._init_vector_store()
 
-        # 构造完整文本
         text = f"表名: {table_name}, 字段: {field_name}, 描述: {field_description}"
         if sample_values:
             text += f", 示例值: {', '.join(sample_values)}"
 
-        # 创建文档
         doc_id = f"{table_name}.{field_name}"
-        doc = LangchainDocument(
+        doc = SimpleDocument(
             page_content=text,
-            metadata={
-                "table_name": table_name,
-                "field_name": field_name,
-                "doc_id": doc_id
-            }
+            metadata={"table_name": table_name, "field_name": field_name, "doc_id": doc_id}
         )
-
-        # 添加到向量存储
-        if self.vector_store is None:
-            self._init_vector_store()
-
-        self.vector_store.add_documents([doc], ids=[doc_id])
+        self._add_documents([doc], [doc_id])
         logger.debug(f"已索引字段: {doc_id}")
 
     def index_document_content(
@@ -103,131 +96,134 @@ class RAGService:
         content: str,
         metadata: Optional[Dict[str, Any]] = None
     ):
-        """
-        将文档内容索引到向量数据库
-
-        Args:
-            doc_id: 文档ID
-            content: 文档内容
-            metadata: 元数据
-        """
+        """将文档内容索引到向量数据库"""
         if not self._initialized:
             self._init_vector_store()
 
-        doc = LangchainDocument(
+        doc = SimpleDocument(
             page_content=content,
             metadata=metadata or {"doc_id": doc_id}
         )
-
-        if self.vector_store is None:
-            self._init_vector_store()
-
-        self.vector_store.add_documents([doc], ids=[doc_id])
+        self._add_documents([doc], [doc_id])
         logger.debug(f"已索引文档: {doc_id}")
 
-    def retrieve(
-        self,
-        query: str,
-        top_k: int = 5
-    ) -> List[Dict[str, Any]]:
-        """
-        根据查询检索相关文档
+    def _add_documents(self, documents: List[SimpleDocument], doc_ids: List[str]):
+        """批量添加文档到向量索引"""
+        if not documents:
+            return
 
-        Args:
-            query: 用户查询
-            top_k: 返回数量
+        texts = [doc.page_content for doc in documents]
+        embeddings = self.embedding_model.encode(texts, convert_to_numpy=True)
+        embeddings = self._normalize_vectors(embeddings).astype('float32')
 
-        Returns:
-            相关文档列表
-        """
+        if self.index is None:
+            self._init_vector_store()
+
+        id_list = [hash(did) for did in doc_ids]
+        id_array = np.array(id_list, dtype='int64')
+        self.index.add_with_ids(embeddings, id_array)
+
+        for doc, did in zip(documents, doc_ids):
+            self.documents.append({"id": did, "content": doc.page_content, "metadata": doc.metadata})
+            self.doc_ids.append(did)
+
+    def retrieve(self, query: str, top_k: int = 5) -> List[Dict[str, Any]]:
+        """根据查询检索相关文档"""
         if not self._initialized:
             self._init_vector_store()
 
-        if self.vector_store is None:
+        if self.index is None or self.index.ntotal == 0:
             return []
 
-        # 执行相似度搜索
-        docs_and_scores = self.vector_store.similarity_search_with_score(
-            query,
-            k=top_k
-        )
+        query_embedding = self.embedding_model.encode([query], convert_to_numpy=True)
+        query_embedding = self._normalize_vectors(query_embedding).astype('float32')
+
+        scores, indices = self.index.search(query_embedding, min(top_k, self.index.ntotal))
 
         results = []
-        for doc, score in docs_and_scores:
+        for score, idx in zip(scores[0], indices[0]):
+            if idx < 0:
+                continue
+            doc = self.documents[idx]
             results.append({
-                "content": doc.page_content,
-                "metadata": doc.metadata,
-                "score": float(score),  # 距离分数，越小越相似
-                "doc_id": doc.metadata.get("doc_id", "")
+                "content": doc["content"],
+                "metadata": doc["metadata"],
+                "score": float(score),
+                "doc_id": doc["id"]
             })
 
         logger.debug(f"检索到 {len(results)} 条相关文档")
         return results
 
     def retrieve_by_table(self, table_name: str, top_k: int = 5) -> List[Dict[str, Any]]:
-        """
-        检索指定表的字段
-
-        Args:
-            table_name: 表名
-            top_k: 返回数量
-
-        Returns:
-            相关字段列表
-        """
+        """检索指定表的字段"""
         return self.retrieve(f"表名: {table_name}", top_k)
 
     def get_vector_count(self) -> int:
         """获取向量总数"""
-        if self.vector_store is None:
+        if self.index is None:
             return 0
-        return len(self.vector_store.docstore._dict)
+        return self.index.ntotal
 
-    def save_index(self, persist_path: str):
-        """
-        保存向量索引到磁盘
+    def save_index(self, persist_path: str = None):
+        """保存向量索引到磁盘"""
+        if persist_path is None:
+            persist_path = self._persist_dir
 
-        Args:
-            persist_path: 保存路径
-        """
-        if self.vector_store is not None:
-            self.vector_store.save_local(persist_path)
+        if self.index is not None:
+            os.makedirs(persist_path, exist_ok=True)
+            faiss.write_index(self.index, os.path.join(persist_path, "index.faiss"))
+            with open(os.path.join(persist_path, "documents.pkl"), "wb") as f:
+                pickle.dump(self.documents, f)
             logger.info(f"向量索引已保存到: {persist_path}")
 
-    def load_index(self, persist_path: str):
-        """
-        从磁盘加载向量索引
+    def load_index(self, persist_path: str = None):
+        """从磁盘加载向量索引"""
+        if persist_path is None:
+            persist_path = self._persist_dir
 
-        Args:
-            persist_path: 保存路径
-        """
-        if not os.path.exists(persist_path):
-            logger.warning(f"向量索引文件不存在: {persist_path}")
+        index_file = os.path.join(persist_path, "index.faiss")
+        docs_file = os.path.join(persist_path, "documents.pkl")
+
+        if not os.path.exists(index_file):
+            logger.warning(f"向量索引文件不存在: {index_file}")
             return
 
         self._init_embeddings()
-        self.vector_store = FAISS.load_local(
-            persist_path,
-            self.embeddings,
-            allow_dangerous_deserialization=True
-        )
+        self.index = faiss.read_index(index_file)
+
+        with open(docs_file, "rb") as f:
+            self.documents = pickle.load(f)
+
+        self.doc_ids = [d["id"] for d in self.documents]
         self._initialized = True
-        logger.info(f"向量索引已从 {persist_path} 加载")
+        logger.info(f"向量索引已从 {persist_path} 加载，共 {len(self.documents)} 条")
 
     def delete_by_doc_id(self, doc_id: str):
         """根据文档ID删除索引"""
-        if self.vector_store is not None:
-            self.vector_store.delete(ids=[doc_id])
+        if self.index is not None:
+            remaining = [d for d in self.documents if d["id"] != doc_id]
+            self.documents = remaining
+            self.doc_ids = [d["id"] for d in self.documents]
+
+            self.index.reset()
+            if self.documents:
+                texts = [d["content"] for d in self.documents]
+                embeddings = self.embedding_model.encode(texts, convert_to_numpy=True)
+                embeddings = self._normalize_vectors(embeddings).astype('float32')
+                id_array = np.array([hash(did) for did in self.doc_ids], dtype='int64')
+                self.index.add_with_ids(embeddings, id_array)
+
             logger.debug(f"已删除索引: {doc_id}")
 
     def clear(self):
         """清空所有索引"""
         self._init_vector_store()
-        if self.vector_store is not None:
-            self.vector_store.delete(ids=list(self.vector_store.docstore._dict.keys()))
+        if self.index is not None:
+            self.index.reset()
+            self.documents = []
+            self.doc_ids = []
             logger.info("已清空所有向量索引")
 
 
-# ==================== 全局单例 ====================
-
 rag_service = RAGService()
diff --git a/backend/requirements.txt b/backend/requirements.txt
index bc2b712..28f756b 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -15,6 +15,7 @@ python-dotenv==1.0.0
 
 # ==================== 数据库 - MySQL (结构化数据) ====================
 pymysql==1.1.0
+aiomysql==0.2.0
 sqlalchemy==2.0.25
 
 # ==================== 数据库 - MongoDB (非结构化数据) ====================
@@ -29,7 +30,7 @@ celery==5.3.4
 
 # ==================== RAG / 向量数据库 ====================
 # chromadb==0.4.22  # Windows 需要 C++ 编译环境，如需安装请使用预编译版本或 WSL
-sentence-transformers==2.2.2
+sentence-transformers==2.7.0
 faiss-cpu==1.8.0
 
 # ==================== 文档解析 ====================
@@ -40,8 +41,6 @@ markdown-it-py==3.0.0
 chardet==5.2.0
 
 # ==================== AI / LLM ====================
-langchain==0.1.0
-langchain-community==0.0.10
 httpx==0.25.2
 
 # ==================== 数据处理与可视化 ====================
diff --git a/frontend/src/pages/ExcelParse.tsx b/frontend/src/pages/ExcelParse.tsx
index 316e459..8556025 100644
--- a/frontend/src/pages/ExcelParse.tsx
+++ b/frontend/src/pages/ExcelParse.tsx
@@ -30,7 +30,7 @@ import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@
 import { Checkbox } from '@/components/ui/checkbox';
 import { toast } from 'sonner';
 import { cn } from '@/lib/utils';
-import { backendApi, type ExcelParseResult, type ExcelUploadOptions, aiApi, analysisChartsApi } from '@/db/backend-api';
+import { backendApi, type ExcelParseResult, type ExcelUploadOptions, aiApi } from '@/db/backend-api';
 import {
   Table as TableComponent,
   TableBody,
@@ -179,7 +179,7 @@ const ExcelParse: React.FC = () => {
     setAnalysisCharts(null);
 
     try {
-      const result = await analysisChartsApi.extractAndGenerateCharts({
+      const result = await aiApi.extractAndGenerateCharts({
         analysis_text: analysisText,
         original_filename: uploadedFile?.name || 'unknown',
         file_type: 'excel'