diff --git a/README.md b/README.md
index f0baf0e..b18c7e8 100644
--- a/README.md
+++ b/README.md
@@ -645,7 +645,39 @@ Book* read1()
 文件保存
 从文件读取
 上述各模块通过主程序（main）进行调用，系统模块图如下:
-
++----------------+       +----------------+
+|     Start      |       |      End       |
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+|   ShowMainMenu |       |   ShowLibInfo  |
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+|   ShowLibBook  |       |    AddBook     |
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+|  DealoldBook   |       |   foundBook    |
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+| foundReader_Info|       | foundReaderInfo|
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+|    LendBook    |       |   returnBook   |
++----------------+       +----------------+
+        |                        |
+        v                        v
++----------------+       +----------------+
+|      save      |       |     read1      |
++----------------+       +----------------+
 
 
 ## 详细设计