Automobile middle door lock mainbody

The invention relates to a main body of door lock of vehicle, which comprises a lock frame, a cover plate, a clamp plate with return spring, a pallet, a pallet spring and a unlock arm. Wherein, the clamp plate is mounted on the rotation axle, while it has claw groove matched with pallet; the pallet is mounted on the rotation axle of pallet; the end of one arm of pallet has the convex claw matched with the claw groove, to compress one end of pallet spring above said arm; another arm of pallet is contacted with unlock arm; when locking, the function force of pallet spring can contact the clamp plate to avoid its rotation; when unlocking, the unlocking arm rotates the pallet, to overcome the force of pallet spring, to release the clamp plate; then the clamp plate will rotate back by the return spring, to unlock. The invention avoids the lock element, internal handle unlocking element, external handle unlocking device and lock pin unlocking element, to simplify the structure.