The utility model provides a door, include: the movably installation in the vehicle is constructed into to the door structure, breech lock mechanism constructs and can release the ground joint with the firing pin to keep the door at closed position, mobilizable handle component, installation house to house (H -H) structure, lengthwise flexible member is operationally with handle member and the interconnect of breech lock mechanism for the user can move the handle member and make lengthwise flexible member shift with unblock breech lock mechanism, based on the locking device of speed, operationally be connected to the aversion of lengthwise flexible member with optionally restriction lengthwise flexible member to prevent if lengthwise flexible member inception when moving with the speed that is higher than the admissible value breech lock mechanism by the unblock. The utility model discloses another kind of door and the locking device based on speed are still provided. The utility model discloses can prevent the unblock in lateral part collision incident of door breech lock.