In order to improve the flow distribution performance of the spherical valve pair of the high-speed and high-pressure miniature axial piston pump,taking the spherical valve pair of the unidirectional rotating miniature axial piston pump as the research object,the structure of pre-boost zone was optimized.The mathematical models of the instantaneous pressure in the pre-boost transition zone,the flow area of the triangular groove and the depth angle of the triangular groove were established.Then particle swarm optimization algorithm was used to optimize the structure of the pre-boost zone.Finally,the original model and the optimized model were imported into Fluent for comparative analysis.The structure optimization results are as follows:depth angle β=16.1°,width angle α=56.3°,opening angle ϕ =12.7°,error angleφ０ =1.2°.After optimization,the pressure pulsation rate in the pre-boost overpressure zone is reduced by 4.6% compared with the original structure,the flow distribution performance of the spherical valve pair of the miniature axial piston pump is improved.