1.只需在终端下输入以下两个命令：
settings set org.gnome.gedit.preferences.encodings auto-detected"['GB18030', 'GB2312', 'GBK', 'UTF-8', 'BIG5', 'CURRENT','UTF-16']"
gsettings set org.gnome.gedit.preferences.encodings shown-in-menu"['GB18030', 'GB2312', 'GBK', 'UTF-8', 'BIG5', 'CURRENT','UTF-16']"
2.重新打开gedit即可！
Ubuntu下Gedit打开Windows记事本.txt文件乱码解决：http://www.linuxdiyf.com/linux/11761.html