For the research and development of high-speed and high-flow fuel piston pumps,a simplified numerical simulation model of the fluid domain was built using the new double-swash-plate piston pump as a prototype,and the pressure pulse mechanism and evolution law of the plunger cavity at different speeds were studied.The pressure pulsation of the piston pump at different speeds was compared,and the influence of speed change on pressure was explored.Combined with the position and pressure changes of the plunger cavity and the distribution plate during the rotation of the piston pump,the causes of pressure fluctuations inside the plunger cavity during operation were studied.The results show that with the increase of speed,the pressure value of each point inside the plunger cavity increases,but the overall pressure fluctuation trend is consistent.The pressure fluctuation inside the plunger cavity is affected by the contact with the distribution plate and the reciprocating movement on the piston side of the piston pump.