Drive device of pneumatic proportional valve

The invention discloses a drive device of a pneumatic proportional valve. The drive device is characterized by comprising a compressed air source, an electromagnetic valve, a controller and a cylinder; a piston is arranged in the cylinder and is driven to move up and down through the pressure difference between the two ends of the piston, and the piston is positioned and stays when the stress of the upper end and the lower end is balanced; the compressed air source provides pressure for an upper end cavity and/or a lower end cavity of the piston of the cylinder by opening or closing the electromagnetic valve; the electromagnetic valve is controlled to be opened and closed through PWM signals provided by the controller. By opening and closing the electromagnetic valve, the valve can be accurately and stably controlled at any position of the working stroke, and linearity is high; the number of elements which are used is small, the structure is simple, all the elements which are used are conventional pneumatic elements, and cost is low.