The invention belongs to the technical field of automobile spare tire auxiliary devices, and provides an automobile spare tire lifting device. One end of a moving rod (4) of the hanging device is connected with a trunk (3), the other end of the moving rod (4) is connected with a motor (5), a cap-shaped locking cover (6) is mounted on a rotating shaft of the motor (5), a meshing gear (7) is arranged in the locking cover (6), a fastening nut (8) is screwed at the upper end of the locking bolt (2), teeth (9) are arranged on the side surface of the fastening nut (8), and the locking cover (6) can be meshed with the fastening nut (8). The automobile spare tire lifting device is simple in structure and low in cost. When an automobile needs to replace an automobile spare tire, the fastening nut for fixing the automobile spare tire can conveniently and rapidly loosen from the locking bolt, the automobile spare tire looses and can conveniently, rapidly and automatically fall on the ground from the trunk, and the labor intensity of an operator is effectively relieved.