Abstract: Cam anti-reverse device is put forward in this paper, which has the similar work principle with the friction anti-reverse device used in nuclear power stations, but has more simple structure, less rotating parts, and smaller size. Against the key problem of the separating speed when the rotates, the simulation model is established based on the theory of fluid lubrication and solved with Matlab language. In the end, combined with a shield pump structure size, the cam anti-reverse device is designed, and the relationship of the forward speed, the degree of deviation and the pressure torque is calculated and analyzed. The results show that the cam anti-reverse device can separate when the rotor speed rises to a certain speed.