According to the formation principle of the tritubercular cycloid in this paper, the rotor, whose bore curve is the inner envelope line of the cycloid, is made with the solid radius vector. A new type of cycloid pump is thus made possible with the special movement of the rotor and stator. The operating principle and the working process of the new cycloid pump are also illustrated and analyzed. In addition, the performances such as the structure of the inner rotor and the external rotor, the displacement of the pump, and the pressure pulsation are analyzed.