Abstract: A differential lock structure includes a differential and a lock ring, wherein the case of the differential has at least one locking through hole, and an output gear inside the differential having a recess, and the lock ring has a locking through bolt for passing through the locking through hole in the recess, and has a lock device for forcing the lock ring to stay close to the differential, characterized in that: the lock device includes an arbor which circumferentially has a worm gear and the other end has a spline gear, and a fork has a worm gear hole matching to the worm gear at one end and the other end clamps the lock ring, and a motor gear has a spline gear hole matching to the spline gear; when the motor gear rotates, the arbor is rotated, and the fork presses the lock ring close to the differential.