linux桌面图标跟windows系统一样，只是个快捷方式，在/usr/share/applications/目录下面有应用程序的启动图标，可以直接复制到桌面，如果这个文件夹下没有的话，可以自己新建一个。
unity-tweak-tool
# 系统图标不见了解决方法
Remove .config,.local, .cache and .fontconfig from your home directory will make your system as it was a new
Follow these simple steps
Open terminal(CTRL+ALT+T, if terminal does not then press CTRL+ALT+F1 to go to CLI tty1 mode) first make a directory as a backup
cd ~
mkdir backup
Then copy above mentioned directories to backup
cp -R .config .local .cache .fontconfig backup/
Then remove all mentioned directories:
rm -r .config .local .cache .fontconfig
Then restart your system
sudo reboot
That's it.. Your system will be rebooted in new default configuration.
https://askubuntu.com/a/342059/861079