diff --git a/设计文档.assets/prefetch.png b/设计文档.assets/prefetch.png
new file mode 100644
index 0000000..977a968
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diff --git a/设计文档.assets/write_1.png b/设计文档.assets/write_1.png
new file mode 100644
index 0000000..74f1245
Binary files /dev/null and b/设计文档.assets/write_1.png differ
diff --git a/设计文档.assets/write_2.png b/设计文档.assets/write_2.png
new file mode 100644
index 0000000..a5ff4fd
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diff --git a/设计文档.md b/设计文档.md
index 635af99..03d7b65 100644
--- a/设计文档.md
+++ b/设计文档.md
@@ -402,7 +402,7 @@ void CheckValid(){
 
 经过perf火焰图测试发现，大多数时间仍用于系统调用read，IO仍然是瓶颈，因此未从本质上解决问题。
 
-![prefetch](设计文档.assets/prefetch.svg)
+![prefetch](设计文档.assets/prefetch.png)
 
 **缺陷2：prefetch数组需要存放所有Value，实践中不可行**
 
@@ -1145,9 +1145,9 @@ getkeysbyfieldproportion=0.001
 
 以下第一张图是fillRandom的火焰图，第二张图是overwrite的火焰图。
 
-![write_1](设计文档.assets/write_1.svg)
+![write_1](设计文档.assets/write_1.png)
 
-![write_2](设计文档.assets/write_2.svg)
+![write_2](设计文档.assets/write_2.png)
 
 ## 7. 分工和进度安排