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