Automobile drive axle differential lock

The invention discloses an automobile drive axle differential lock which is characterized by being composed of an axle housing, a bearing seat, a piston ring, a baffle, a clamp spring, a movable meshing sleeve, a return spring, an air pipe connector and an O-shaped ring. An inner hole of the bearing seat is used for assembling an oil seal and a bearing, the end part of the bearing seat is provided with a cavity capable of assembling a piston ring, and the piston ring assembly assembled with the O-shaped ring is arranged in the cavity of the bearing seat together to form a cylinder with a compression function; when high-pressure air enters the cavity of the bearing seat through the air channel and the air pressure reaches a certain value, the piston ring overcomes the pressure of the return spring and pushes the end face teeth of the sliding meshing sleeve to be combined with the end face teeth of the differential mechanism left shell, so that the differential mechanism assembly forms a rigid body, and the dif