When i use a modelmake the door, my player can go through it, so don't need key
to open it .......... very funny? So how to repair this problem? Please help me!

if your using a modle, your character will go through it. I ran into this problem once myself.

In Wed make the door as a new map. save it in the game directory. build it.

open up your leve and add map_entity > door

give it the door action.

done/

Good luck.