Air release valve and air pressure driven toilet water tank drain valve

An air release valve, comprising a valve seat, a sliding block and a push block, wherein the valve seat is arranged at an upper part of the drain valve body through a mounting seat, a bottom of the valve seat is provided with an air release channel, one end of the air release channel is an air inlet, the other end of the air release channel forms an air release nozzle, the sliding block is located above the air release nozzle and is slidably arranged on the valve seat, and a bottom of the sliding block is provided with a sealing gasket for sealing the air release nozzle, a compressed elastic element is arranged between a side of the sliding block away from an inner core tube of the drain valve and the valve seat, a limit bump is arranged at a side of the sliding block close to the inner core tube of the drain valve, a limit stopper for clamping the limit bump is arranged at the valve seat, an upper stopper and a lower stopper are arranged at the side of the sliding block close to the inner core tube of the drain valve, a lower part of the upper stopper is an inclined plane, and the push block is arranged between the upper stopper and the lower stopper and is arranged at an upper part of the inner core tube of the drain valve.