Reboot function openwrt-21.02

I compile the openwrt-21.02 for HLK7628N. build is good. but reboot command can not running. If I lose some configure?

Are you saying your settings are lost after a reboot? Because that means your device has no writable /overlay partition. That's almost always because it doesn't have enough flash anymore for OpenWrt to create such a partition. Settings will then get saved to RAM, which means they are lost upon reboot.

root@OpenWrt:/# reboot
root@OpenWrt:/# [   68.193609] reboot: Restarting system

Stay here

The commit adding support shows a GPIO being defined for reset:

Maybe try contacting the author? I'm not sure if he's on the forums here but his e-mail address is in the commit.