The stability of the output flow of variable flow axial piston pump is an important index to judge its performance.The throttling groove on the valve plate has a significant impact on the flow pulsation,which will cause pressure pulsation.In order to reduce the flow pulsation of variable flow axial piston pump,the variable flow axial piston pump model was established with AMESim,the calculation formulae of throttling groove overflow area were given,the throttling groove overflow area diagrams were drawn with MATLAB,and the numerical values were imported into the column plug model for simulation analysis.It is found that when the plunger cavity is just connected with the oil pressure cavity,the flow backflow phenomenon is positively correlated with the overflow area,and the flow pulsation is negatively correlated with the overflow area as the plunger cavity continues to rotate.Then,according to the research,a V-trapezoidal throttling groove was designed to effectively improve the performance of variable flow axial piston pump.