Abstract: This paper is going to analyse mainly the inherent theory on how the swash plate type piston pump does produce noise, Point out the focus of designing to reduce the noise, Find out the formula for calculating the orifice and triangular groove of reducing noise valve plate, And calculate the changing curve of liquid pressure in piston chamber by computer, And finally confirm the correctness of the designing method through experiments.

Key words: 压力脉动, 噪声, 柱塞泵