diff --git a/server/knowledge_base/utils.py b/server/knowledge_base/utils.py
index f1dbb47..2bcb353 100644
--- a/server/knowledge_base/utils.py
+++ b/server/knowledge_base/utils.py
@@ -11,6 +11,7 @@ from configs import (
     TEXT_SPLITTER_NAME,
 )
 import importlib
+from text_splitter import zh_third_title_enhance
 from text_splitter import zh_second_title_enhance
 from text_splitter import zh_first_title_enhance
 import langchain.document_loaders
@@ -371,6 +372,7 @@ class KnowledgeFile:
             return []
         #先给二级下 被分开的三级目录分块 增加二级标题，再给分开的二级目录增加一级标题，然后给整个文档的所有分块增加文档标题分块       
         if zh_title_enhance:
+            docs = zh_third_title_enhance(docs)
             docs = zh_second_title_enhance(docs)
             docs = zh_first_title_enhance(docs)
             docs = customize_zh_title_enhance(docs)
diff --git a/text_splitter/__init__.py b/text_splitter/__init__.py
index 44baf2d..49821d5 100644
--- a/text_splitter/__init__.py
+++ b/text_splitter/__init__.py
@@ -2,5 +2,6 @@ from .chinese_text_splitter import ChineseTextSplitter
 from .ali_text_splitter import AliTextSplitter
 from .zh_title_enhance import zh_title_enhance
 from .chinese_recursive_text_splitter import ChineseRecursiveTextSplitter
+from .zh_second_title_enhance import zh_third_title_enhance
 from .zh_second_title_enhance import zh_second_title_enhance
-from .zh_second_title_enhance import zh_first_title_enhance
\ No newline at end of file
+from .zh_second_title_enhance import zh_first_title_enhance
diff --git a/text_splitter/chinese_recursive_text_splitter.py b/text_splitter/chinese_recursive_text_splitter.py
index 5712d15..78f8e55 100644
--- a/text_splitter/chinese_recursive_text_splitter.py
+++ b/text_splitter/chinese_recursive_text_splitter.py
@@ -9,6 +9,7 @@ logger = logging.getLogger(__name__)
 First_SEPARATOE = "\n\n\n\n\n\n\n\n\n\n"
 Second_SEPARATOE = "\n\n\n\n\n\n\n\n"
 Third_SEPARATOE = "\n\n\n\n\n\n"
+Fourth_SEPARATOE = "\n\n\n\n"
 def _split_text_with_regex_from_end(
         text: str, separator: str, keep_separator: bool
 ) -> List[str]:
@@ -41,7 +42,8 @@ class ChineseRecursiveTextSplitter(RecursiveCharacterTextSplitter):
         self._separators = separators or [
             First_SEPARATOE,
             Second_SEPARATOE,
-            Third_SEPARATOE
+            Third_SEPARATOE,
+            Fourth_SEPARATOE
             #"\n\n",
             #"\n",
             # "。|！|？",
@@ -60,21 +62,26 @@ class ChineseRecursiveTextSplitter(RecursiveCharacterTextSplitter):
         separator = separators[-1]
         new_separators = []
         if self.is_recursive == False:
+            #一级目录
             text = re.sub(r'(\n+前\s+言\n+)',  r"\n\n\n\n\n\n\n\n\n\n\1", text) #通过前言分块
             text = re.sub(r'(\n+\d+[^\S\n]+[^\s\.]+)', r"\n\n\n\n\n\n\n\n\n\n\1", text) #通过1 这样的
             text = re.sub(r'(手工分段\*\*\s*)', r"\n\n\n\n\n\n\n\n\n\n", text)  # 将“手工分段**”替换
             text = re.sub(r'(\n+第\s*\S+\s*章\s+)', r"\n\n\n\n\n\n\n\n\n\n\1", text)  # 通过第 章
-            #text = re.sub(r'(\n+表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)', r"\n\n\n\n\n\n\n\n\n\n\1", text)  # 通过表 A.2
             
+            #二级目录
             text = re.sub(r'(\n+表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)', r"\n\n\n\n\n\n\n\n\1", text)  # 通过表 A.2
             text = re.sub(r'(\n+(?<!\.|[a-zA-Z0-9])[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))', r"\n\n\n\n\n\n\n\n\1", text)  # 通过\n1.2 这样的章和节来分块
             text = re.sub(r'(\n+第\s*\S+\s*条\s+)', r"\n\n\n\n\n\n\n\n\1", text)  # 通过第 条
             text = re.sub(r'(\n+第\s*\S+\s*条(:|：))', r"\n\n\n\n\n\n\n\n\1", text)  # 通过第 条
             text = re.sub(r'(\n+(一、|二、|三、|四、|五、|六、|七、|八、|九、|十、|十一、|十二、|十三、|十四、|十五、|十六、|十七、|十八、|十九、|二十、))', r"\n\n\n\n\n\n\n\n\1", text)  # 通过第 条
             
+            #三级目录
             text = re.sub(r'(\n+(?<!\.|[a-zA-Z0-9])[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))', r"\n\n\n\n\n\n\1", text)  # 再通过 1.2.3 
-            text = re.sub(r'(\n+(（一）|（二）|（三）|（四）|（五）|（六）|（七）|（八）|（九）|（十）|（十一）|（十二）|（十三）|（十四）|（十五）|（十六）|（十七）|（十八）|（十九）|（二十）))', r"\n\n\n\n\n\n\1", text)  # 通过第 条
-            text = re.sub(r'(\n+(\(一\)|\(二\)|\(三\)|\(四\)|\(五\)|\(六\)|\(七\)|\(八\)|\(九\)|\(十\)|\(十一\)|\(十二\)|\(十三\)|\(十四\)|\(十五\)|\(十六\)|\(十七\)|\(十八\)|\(十九\)|\(二十\)))', r"\n\n\n\n\n\n\1", text)  # 通过第 条
+            text = re.sub(r'(\n+(（一）|（二）|（三）|（四）|（五）|（六）|（七）|（八）|（九）|（十）|（十一）|（十二）|（十三）|（十四）|（十五）|（十六）|（十七）|（十八）|（十九）|（二十）))', r"\n\n\n\n\n\n\1", text) 
+            text = re.sub(r'(\n+(\(一\)|\(二\)|\(三\)|\(四\)|\(五\)|\(六\)|\(七\)|\(八\)|\(九\)|\(十\)|\(十一\)|\(十二\)|\(十三\)|\(十四\)|\(十五\)|\(十六\)|\(十七\)|\(十八\)|\(十九\)|\(二十\)))', r"\n\n\n\n\n\n\1", text) 
+            
+            #四级目录
+            text = re.sub(r'(\n+(?<!\.|[a-zA-Z0-9])[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))', r"\n\n\n\n\1", text)  # 再通过 1.2.3
             text = text.rstrip()  # 段尾如果有多余的\n就去掉它
             self.is_recursive = True
         for i, _s in enumerate(separators):
diff --git a/text_splitter/zh_second_title_enhance.py b/text_splitter/zh_second_title_enhance.py
index a406c09..729ddf4 100644
--- a/text_splitter/zh_second_title_enhance.py
+++ b/text_splitter/zh_second_title_enhance.py
@@ -17,7 +17,7 @@ def get_fist_level_title(
     if ENDS_IN_PUNCT_RE.search(first_line) is not None:
         return ""
   
-    FIRST_TITLE = r'((?<!.)\d+[^\S\n]+[^\s\.]+\S+)'
+    FIRST_TITLE = r'((?<!.)\d+[^\S\n]+[^\s\.]+\S+|(?<!.)第\s*\S+\s*章\s+)'
     TITLE_PUNCT_RE = re.compile(FIRST_TITLE)
     if TITLE_PUNCT_RE.search(first_line) is not None:
         return first_line
@@ -40,7 +40,7 @@ def get_second_level_title(
     if ENDS_IN_PUNCT_RE.search(first_line) is not None:
        return ""
            
-    Second_TITLE = r'((?<!.)[0-9]+\s*\.\s*[0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))'
+    Second_TITLE = r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9])|(?<!.)第\s*\S+\s*条\s+|(?<!.)第\s*\S+\s*条(:|：)|(?<!.)(一、|二、|三、|四、|五、|六、|七、|八、|九、|十、|十一、|十二、|十三、|十四、|十五、|十六、|十七、|十八、|十九、|二十、))'
     TITLE_PUNCT_RE = re.compile(Second_TITLE)
     if TITLE_PUNCT_RE.search(first_line) is not None:
         return first_line
@@ -63,7 +63,7 @@ def is_second_level_content(
     splitlines = text.splitlines()
     first_line = splitlines[0]
    
-    Second_TITLE = r'((?<!.)[0-9]+\s*\.\s*[0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))|(?<!.)(表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)'
+    Second_TITLE = r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))|(?<!.)(表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)|(?<!.)第\s*\S+\s*条\s+|(?<!.)第\s*\S+\s*条(:|：)|(?<!.)(一、|二、|三、|四、|五、|六、|七、|八、|九、|十、|十一、|十二、|十三、|十四、|十五、|十六、|十七、|十八、|十九、|二十、)'
     TITLE_PUNCT_RE = re.compile(Second_TITLE)
     if TITLE_PUNCT_RE.search(first_line) is not None:
         return True
@@ -82,13 +82,83 @@ def is_third_level_content(
     splitlines = text.splitlines()
     first_line = splitlines[0]
    
-    Third_TITLE = r'((?<!.)[0-9]+\s*\.\s*[0-9]+\s*\.\s*[0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))|((?<!.)表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)'
+    Third_TITLE = r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))|((?<!.)表\s*[A-Za-z0-9]+(\s*\.\s*[A-Za-z0-9]+)*\s+)|((?<!.)（一）|（二）|（三）|（四）|（五）|（六）|（七）|（八）|（九）|（十）|（十一）|（十二）|（十三）|（十四）|（十五）|（十六）|（十七）|（十八）|（十九）|（二十）)|((?<!.)(\(一\)|\(二\)|\(三\)|\(四\)|\(五\)|\(六\)|\(七\)|\(八\)|\(九\)|\(十\)|\(十一\)|\(十二\)|\(十三\)|\(十四\)|\(十五\)|\(十六\)|\(十七\)|\(十八\)|\(十九\)|\(二十\)))'
     TITLE_PUNCT_RE = re.compile(Third_TITLE)
     if TITLE_PUNCT_RE.search(first_line) is not None:
         return True
             
     return False
+
+def get_third_level_title(
+        text: str,
+) -> str:
+    # 文本长度为0的话，肯定不是title
+    if len(text) == 0 and len (text)>= 25:
+        print("Not a title. Text is empty or longer than 25.")
+        return ""
     
+    splitlines = text.splitlines()
+    first_line = splitlines[0]
+    # 文本中有标点符号，就不是title
+    ENDS_IN_PUNCT_PATTERN = r"[^\w\s]\Z"
+    ENDS_IN_PUNCT_RE = re.compile(ENDS_IN_PUNCT_PATTERN)
+    if ENDS_IN_PUNCT_RE.search(first_line) is not None:
+       return ""
+           
+    Third_TITLE = r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))'
+    TITLE_PUNCT_RE = re.compile(Third_TITLE)
+    if TITLE_PUNCT_RE.search(first_line) is not None:
+        return first_line
+    else:
+        if len(splitlines)>1:
+            Second_line = splitlines[1]
+            if TITLE_PUNCT_RE.search(Second_line) is not None:
+                return Second_line
+    return ""
+
+#judge if it is 4th level content
+def is_fourth_level_content(
+        text: str,
+) -> bool:
+    # 文本长度为0的话，肯定不是title
+    if len(text) == 0:
+        print("Not a title. Text is empty.")
+        return False
+    
+    splitlines = text.splitlines()
+    first_line = splitlines[0]
+   
+    Third_TITLE = r'((?<!.)[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+\s*\.\s*[a-zA-Z0-9]+[^\S\n]+[^\s\.]+(?!\.|[a-zA-Z0-9]))'
+    TITLE_PUNCT_RE = re.compile(Third_TITLE)
+    if TITLE_PUNCT_RE.search(first_line) is not None:
+        return True
+            
+    return False
+
+#给四级被分开的内容 增加三级标题
+def zh_third_title_enhance(docs: Document) -> Document:
+    title = None
+    print(f"zh_third_title_enhance ....")
+    if len(docs) > 0:
+        for doc in docs:
+            print(f"zh_third_title_enhance: {doc}")
+            third_title = get_third_level_title(doc.page_content)
+            if third_title:
+                title = third_title
+                print(f"title: {title}")
+            elif title:
+                print(f"title is not none")
+                temp_fourth_content = is_fourth_level_content(doc.page_content)
+                if temp_fourth_content:
+                    print(f"is_fourth_level_content : {temp_fourth_content}")
+                    doc.page_content = f"{title} {doc.page_content}"
+                else:
+                    title = None
+            print(f"final title: {title}")
+        return docs
+    else:
+        print("zh_third_title_enhance 文件不存在")
+
 #给三级被分开的内容 增加二级标题
 def zh_second_title_enhance(docs: Document) -> Document:
     title = None