感谢BakaSoniji提供汉化.
安装:

yum install git -y
cd /usr/local/directadmin/data/skins/evolution/lang/
git clone https://github.com/BakaSoniji/DirectAdmin-EvolutionSkin-SimplifiedChinese.git SimplifiedChinese_Git
ln -s SimplifiedChinese_Git/zh_Hans.po zh_Hans.po
ln -s SimplifiedChinese_Git/login-zh_Hans.po login-zh_Hans.po
chown -R diradmin.diradmin /usr/local/directadmin/data/skins/evolution/lang


更新:
cd /usr/local/directadmin/data/skins/evolution/lang/SimplifiedChinese_Git/
git pull