1、下载texlive2019的iso文件，清华镜像地址：https://mirrors.tuna.tsinghua.edu.cn/CTAN/systems/texlive/Images/texlive2019-20190410.iso
2、挂载后，进入目录，有一个安装文件：install-tl
3、用sudo权限运行，./install-tl
4、有时候，因为权限问题无法安装到/usr/local目录下，需要按“D"，修改到HOME目录，这样就有权限了。
5、修改后，就可运行”I“，命令进行安装了，大约有3000+的文件。
6、仔细的按install-tl的提示，写的很清楚的。ok
Welcome to TeX Live! See /home/jack/texlive/2019/index.html for links to documentation. The TeX Live web site (https://tug.org/texlive/) contains any updates and corrections. TeX Live is a joint project of the TeX user groups around the world; please consider supporting it by joining the group best for you. The list of groups is available on the web at https://tug.org/usergroups.html. Add /home/jack/texlive/2019/texmf-dist/doc/man to MANPATH. Add /home/jack/texlive/2019/texmf-dist/doc/info to INFOPATH. Most importantly, add /home/jack/texlive/2019/bin/x86_64-linux