Abstract: A compressed air single-action actuator includes an actuator body, a solenoid valve is provided in the actuator body, a solenoid valve plate is provided between the actuator body and the solenoid valve, a gas chamber is provided on the side face of the actuator body, an O-ring seal is provided between the gas chamber and the actuator body; a first inlet passage communicated with the gas chamber is provided on the actuator body, a check valve is provided at one end of the gas chamber of the first gas inlet passage, the other end of the outlet is provided at a right back side of the Namur interface; a second gas inlet passage is provided on the actuator body communicated with the gas chamber, the outlet of the second gas inlet passage is provided at an upper left side of the Namur interface.