The fuel piston pump is the core power component of the aircraft engine fuel control system. The key technology of improving the reliability of the pump is the suppressing of the cavitation at the interface between the valve plate and the cylinder block. This article aims to solve the problem of cavitation caused by high temperature in the process of suction and discharge. The theoretical model of cavitation related to the interface is established. The influence of different working conditions and valve plate structures are considered, and the performance such as gas volume fraction and pulsation are analyzed separately. A new valve plate with combined damping groove is proposed. A hydraulic system test rig to verify the performance of the pump is built. In summary, the results of simulation and test show that the new combined damping groove effectively suppress the cavitation at the interface under high temperature. The non-cavitation time of the fuel piston pump is extended from 20h to 450h, which significantly improves its reliability.