The invention discloses a method for improving pressure pulsation of a mixed-flow type pump turbine. The method for improving the pressure pulsation of the mixed-flow type pump turbine comprises choosing the appropriate number Zg of movable guide vanes, defining the reasonable diameter Dg of a distribution circle of the guide vanes, defining the reasonable distance delta from a rotating wheel to a fixed edge and the like. The method for improving the pressure pulsation of a mixed-flow type pump turbine aims at achieving the purpose of improving forward pressure pulsation of a back rotating wheel of the guide vanes of the mixed-flow type pump turbine and improving the operational stability of a pump storage group.