diff --git a/file_object.py b/file_object.py
index b9e3e7a..f56a35f 100644
--- a/file_object.py
+++ b/file_object.py
@@ -68,6 +68,22 @@ class SFileObject:
         content = self._content
         content[index][7] = new_height
 
+    # 更新档距
+    def update_all_mileage(self, new_mileage_dic):
+        content = list(self._content)
+        first_tower_number_in_s = self._content[2][0]
+        tower_mileage_of_first_tower_in_ta = new_mileage_dic[first_tower_number_in_s]
+        for index, s_entry in enumerate(self._content):
+            if s_entry[0] == "首端转角号" or s_entry[0] == "塔号":
+                continue
+            tower_number = s_entry[0]
+            if tower_number in new_mileage_dic:
+                new_mileage = (
+                    new_mileage_dic[tower_number] - tower_mileage_of_first_tower_in_ta
+                )
+                content[index][1] = new_mileage
+        self._content = content
+
 
 # 把所有S文件当做一个来操作
 class SFileAsSingle:
@@ -98,6 +114,16 @@ class SFileAsSingle:
             s_file_obj.write(s_output_file_path)
             print("update S file {Ss}".format(Ss=s_output_file_path))
 
+    # 写入一次S文件
+    def update_all_mileage(self, new_mileage_dic):
+        s_file = self._s_files
+        for s in s_file:
+            s_object = SFileObject(s)
+            s_object.update_all_mileage(new_mileage_dic)
+            s_output_file_path = s_object.file_path
+            s_object.write(s_output_file_path)
+            print("update mileage in S file {Ss}".format(Ss=s_output_file_path))
+
     def content(self):
         s_file = self._s_files
         for s in s_file:
@@ -114,6 +140,7 @@ class TaFileObject:
         self._read(file_path)
         self._old_tower_height_record = None
         self._SFile = SFile
+        self._old_span_record = None  # 档距
         pass
 
     def _read(self, file_path):
@@ -128,7 +155,8 @@ class TaFileObject:
                 contents.append(sep)
         return contents
 
-    def _make_tower_height_record(self, contents):  # 将TA文件读入内存字典中
+    @staticmethod
+    def _make_tower_height_record(contents):  # 将TA文件读入内存字典中
         tower_height_record = {}
         for content in contents:
             sep = content
@@ -138,10 +166,21 @@ class TaFileObject:
                 tower_height_record[tower_number] = tower_height
         return tower_height_record
 
-    def sync_changed_tower_height_to_S(self, new_contents, old_tower_height_record):
+    # def _make_span_record(self, ta_content):  # 将TA 文件档距读入字典中。
+    #     tower_span_record = {}
+    #     basic_mileage = 0
+    #     for ta_entry in ta_content:
+    #         if len(ta_entry) > 2:
+    #             tower_number = ta_entry[0]
+    #             tower_mileage = ta_entry[2]
+    #             tower_span_record[tower_number] = tower_mileage - basic_mileage
+    #             basic_mileage = tower_mileage
+    #     return tower_span_record
+
+    def sync_changed_tower_height_to_S(self, ta_new_contents, old_tower_height_record):
         updated = False
-        for content in new_contents:
-            sep = content
+        for ta_entry in ta_new_contents:
+            sep = ta_entry
             if len(sep) > 9:
                 tower_number = sep[0]
                 old_tower_height = float(old_tower_height_record[tower_number])
@@ -160,6 +199,32 @@ class TaFileObject:
                     updated = True
         return updated
 
+    def sync_all_tower_mileage_to_s(self):
+        ta_new_contents = self._read(self._file_path)
+        new_mileage_dic = {}
+        for ta_entry in ta_new_contents:
+            if len(ta_entry)>2:
+                tower_number = ta_entry[0]
+                new_tower_mileage = float(ta_entry[2])
+                new_mileage_dic[tower_number] = new_tower_mileage
+        SFile = self._SFile
+        s_as_single = SFileAsSingle(SFile)
+        s_as_single.update_all_mileage(new_mileage_dic)
+
+    # # 同步Ta文件中修改过的档距。
+    # @staticmethod
+    # def sync_changed_tower_span_to_s(ta_new_contents, old_tower_span_record):
+    #     for ta_entry in ta_new_contents:
+    #         tower_number = ta_entry[0]
+    #         old_tower_span = float(old_tower_span_record[tower_number])
+    #         new_tower_span = float(ta_entry[2])
+    #         if abs(old_tower_span - new_tower_span) > 1e-5:
+    #             print(
+    #                 "{tower_number} span changes to {new_tower_span}".format(
+    #                     tower_number=tower_number, new_tower_span=new_tower_span
+    #                 )
+    #             )
+
     def sync_all_tower_height_from_TA_to_S(self):
         enter_string = input("Will synchronize all height from TA to S. Enter AH2S:\n")
         if enter_string.lower() != "ah2s":