Gear pump is a common fluid transmission and conveying element. Because of its simple structure, high efficiency and not easy to be polluted by oil, it is widely used in aviation, aerospace, ships and automobiles and other fields.With the advancement and development of science and technology, the requirements for the performance of gear pumps are getting higher and higher, which is mainly reflected in the realization of high-speed, miniaturization and high-pressure gear pumps.In order to obtain a high-performance gear pump, it is necessary to study and analyze the new problems arising from the high-pressure, high-speed and miniaturization of the gear pump, and to make corresponding improvements and designs for the problems found, so as to provide future research on high-performance gear pumps. A basic model and method.Gear pump rotor is the core component of gear pump, and it is also the foundation and key point of this thesis.In order to solve the problem that the oil trapping phenomenon intensifies and the flow pulsation increases after the pressure rises and the rotational speed increase, this paper firstly establishes the basic mathematical model of the gear pump rotor tooth shape, that is, the tooth shape is composed of "arc-involute-circle" "Arc" three-segment curves are spliced together.The performance of the gear pump is analyzed according to the tooth shape parameters. By setting the helix angle, modulus and tooth width, the phenomenon of trapped oil and a part of the flow pulsation caused by trapped oil are theoretically eliminated, and the theoretical performance of the gear pump is realized. The phenomenon of no trapped oil provides a basic model for the follow-up research of this paper.