Here is my solution: (1) open “options”->”permulink”; (2) set the option back, but don’t save it, just leave the brwoser open; (3) as the .htaccess has been created inside the server, and http service is crashed already, but you can still use file management functionality provided by the space host to delete that file (4) turn back to the browser and save it, done.
ps. if your space host doesn’t support file management, you can upload a phpmyadmin by your own and operate on it.
thank yanzhg for your kind reminder.