The pneumatic nuclear grade eccentric rotary valve is composed by the pneumatic actuators and eccentric rotary valve two parts. The pneumatic actuator has two forms, 35 spring return type cylinder diaphragm actuators (hereinafter referred to as cylinder diaphragm actuators). The structure of eccentric rotating is new.The valve body looks like a round cylinder.The center of the spherical valve core and valve spindle rotation center, designed a eccentricity between when rotating valve shaft drives the valve core, the valve core sphere relatively rotates towards the eccentric rotating body center. When the valve core of soft arm elastic deformation occurs, the spherical valve core and valve seat are stuck tightly to achieve reliable sealing, so the valve is also called the CAM flexure valve.