看到 jira 上也有大量提交 https://jira.atlassian.com/browse/SRCTREEWIN-14551

我采用的解决方案是：

Just wanted to add that i experience this issue too on a large codebase ( IfcOpenshell ) hanging: fetching commits never finishes since 3.4.27 3.4.27 also introduced some sort of endless refresh loop when switching to a branch with many commits 3.4.28 seemed to have improved that somewhat, but ultimately it hangs too when fetching a lots of commits switching back to 3.4.26 cured both the issues in my case

在这里下载 3.4.26 版本
https://www.sourcetreeapp.com/download-archives