Abstract: The components, main parameter and curve equation of cycloid rotor curve for two or three leaves rotor are described. The design demands and optimizing method of rotor curve are put forward. To cycloid rotor curve, the optimizing design and inner leak models, for the purpose of minimal volume and lightest weight are created. The actual curve ascertain method is given according to pump’s inner leak. All above founds the base of un-contact rotor pump design. An example about curve design is provided at last.

Key words: Curve, Design, Pump, Rotor