I found out. Tex file, that is, the file you want to compile, can be compiled in \ctex\MiKTeX\miktex\bin\. Today, I have been tossing for a long time, because I have been unable to compile it, and I have tried to compile it online, but the online one is particularly poor, and I have always said that my template is wrong. . . I am speechless, and the result can be compiled into PDF. Don't worry, I just practiced this method ~ ~ pay attention to this, for example, if you install a complete CTeX! There seems to be another way. I just tried, and it didn't work.