OneCm First, general considerations for improving performance are summarized in the FAQs of the spine-unity documentation, so please take a look if you haven't already: 常见问题 - FAQ 性能问题
Also, if a skeleton has multiple atlas pages, but it is difficult to fit them on one page due to many skins, etc., it may be better to repack the atlas pages with only the images that are actually displayed at runtime. See the "运行时重打包" section of the documentation for more information:
https://zh.esotericsoftware.com/spine-unity#%E7%BB%84%E5%90%88%E7%9A%AE%E8%82%A4
