The invention relates to a centrifugal pump improvement method used for reducing pressure pulse in a centrifugal pump. The method includes the steps that a sensor is used for testing inlet and outlet pressure of the centrifugal pump under the designed working condition; three-dimensional modeling is conducted on the centrifugal pump, numerical simulation is conducted, the maximum value of the frequency domain transformation amplitude of the pressure pulse in the centrifugal pump and the generation position are analyzed according to a numerical simulation result, and the maximum value and the position serve as the improved design target; design of multiple schemes of an impeller and a volute is conducted according to geometrical parameters of the impeller and the volute of the centrifugal pump, and the maximum value of the pressure pulse in each scheme is obtained; a second-order approximate function between the improved design target and the main geometrical parameters of the impeller and the volute is established, the second-order approximate function is optimized, and an optimal parameter combination of the impeller and the volute is obtained; and three-dimensional modeling and numerical simulation are conducted according to the optimal parameters of the impeller and the volute, the improvement scheme is determined through comparison, and the pressure pulse in the centrifugal pump is reduced. By means of the improvement method, the function of reducing the pressure pulse in the centrifugal pump can be achieved.