1.cp /usr/share/doc/sddm/sddm.conf /etc/sddm.conf
2.vim /etc/sddm.conf
[Users]
# Default $PATH for logged in users
DefaultPath=/bin:/usr/bin
# Comma-separated list of shells.
# Users with these shells as their default won't be listed
HideShells=/usr/sbin/nologin,/bin/false
# Comma-separated list of users that should not be listed
HideUsers=sync
#通过HideShells和HideUsers隐藏应用用户
# Maximum user id for displayed users
MaximumUid=60000
# Minimum user id for displayed users
MinimumUid=0
#主要是这一行MinimumUid修改为0后才能使用root用户
# Remember the session of the last successfully logged in user
RememberLastSession=true
# Remember the last successfully logged in user
RememberLastUser=true
3.vim /etc/pam.d/sddm
#auth required pam_succeed_if.so user != root quiet_success
auth sufficient pam_succeed_if.so user ingroup nopasswdlogin