打开TortoiseSVN的Setting，选择左边的Diff Viewer
设置如下：
"D:\Program Files\Beyond Compare 4\BComp.exe" %base %mine /title1=%bname /title2=%yname /leftreadonly
和
"D:\Program Files\Beyond Compare 4\BComp.exe"
其中D:\Program Files\Beyond Compare 4\BComp.exe 为Beyond Compare 4的安装路径
如下图
Merge Tool设置下
"D:\Program Files\Beyond Compare 4\BCompare.exe" %mine %theirs %base %merged /title1=%yname /title2=%tname /title3=%bname /title4=%mname