Rear anti-collision device for automobile and control method

The invention relates to a rear anti-collision device for an automobile. The rear anti-collision device comprises a rear longitudinal beam body, an energy absorption box and a rear anti-collision beam. The rear anti-collision device further comprises a control module, a lifting module and a sensor, the sensor is arranged on the rear anti-collision beam or the energy absorption box and used for monitoring whether the rear anti-collision beam is collided or not, the sensor is electrically connected with the control module, and the control module is electrically connected with the lifting module. The control module controls the lifting module to ascend and descend by receiving collision information transmitted by the sensor, and the lifting module is used for descending to make contact with the road surface and transmitting collision force to the road surface. Compared with the prior art, the structure of the rear portion of the automobile can be reinforced; collision force can be transmitted to the road surface