The pneumatic actuator of the GIQ-AB series pneumatic high vacuum butterfly valve is powered by compressed air. By changing the direction of the air circuit through an electromagnetic directional valve, the mechanical transmission of the piston rack and gear is pushed, and the angular stroke output torque is used to drive the butterfly valve for opening and closing motion, thereby achieving the purpose of connecting or cutting off the air flow in the vacuum pipeline. The valve plate of the valve adopts a clamping structure, which clamps the sealing ring of the valve plate and has a fine adjustment main sealing function. It is a new type of pneumatic high vacuum butterfly valve controlled by pneumatic actuators, divided into double acting and single acting (spring return) cylinders. Optional feedback signal device and electrical valve locator. The applicable working medium is air and non corrosive gases.