The invention belongs to the technical field of vending machines, particularly relates to an automatic bag discharging device of a vending machine, and provides the following scheme aiming at the problems that goods cannot be received by a bag discharging device in the patent, the goods damaged when falling down in the bag discharging process, and meanwhile, the goods cannot be supplemented in time after being sold. The automatic bag discharging device comprises a vending machine body, servo motors are fixed to the inner walls of the two sides of the vending machine body through screws, the output shafts of the servo motors are connected with lead screws through couplers, the outer walls of the lead screws are sleeved with sliding plates, and lifting plates are arranged on the outer wallsof the sliding plates. According to the present invention, a buffer spring and a foam pad can achieve a good buffer effect, goods can be prevented from being broken, the sales quality of the goods isimproved; a piston rod of an electric telescopic rod is controlled to extend, and a push plate can push the goods into a goods discharging barrel from a goods discharging barrel, so that the automaticgoods supplementation is achieved, operation is convenient, maintenance is convenient, and the use requirements of people are met.