The invention relates to an air pressure disc brake which comprises a brake support, a pincer body, a push disc, a pressure base, an eccentric shaft, a bevel gear, an angle gear, a one-way clutch, a gear transmission unit and a screw pushing unit. The pressure base is slidably connected to the pincer body. The eccentric shaft comprises a shaft body and an eccentric disc which is not coaxial with the shaft body. When the eccentric shaft rotates around an axis of the shaft body, the eccentric disc drives the pressure base to do rectilinear translation motion. The bevel gear is arranged on the eccentric shaft, a gap is formed between an adjusting block and an adjusting groove, and through matching between the adjusting block and the adjusting groove, and the coaxial rotation of the bevel gear and the eccentric shaft can be achieved. The angle gear is meshed with the bevel gear, and the angle gear is connected with the gear transmission unit through the one-way clutch in a transmission mode. The gear transmission unit drives the screw pushing unit in a transmission mode, and the screw pushing unit drives the push disc. The air pressure disc brake has the advantages that strength of braking force is not influenced by a brake pincer body structure, transmission ratio of the brake force can be increased, so that the brake force needed by vehicles can be reached, and stability of brake clearance is good.