The invention relates to a hydraulic design method of a high-lift axial flow pump impeller. Main geometric parameters of the impeller are provided, and include a maximum thickness delta max of axial flow pump blades, a molded line radius R, an impeller blade number z, an impeller hub side cascade solidity Sh, an impeller rim side cascade solidity S0, a blade inlet placing angle beta 1, a blade outlet placing angle beta 2, a blade inlet axial surface speed vm1, a blade outlet axial surface speed vm2, a blade outlet peripheral component speed vu2, an impeller diameter D, an impeller hub ratio Rd, an impeller lift coefficient psi, an impeller inlet hub diameter d2, an impeller hub dispersion angle alpha, an impeller round nut height hb, a blade outlet placing angle coefficient K beta 2, a blade inlet placing angle coefficient K beta 1, selection of wing sections with different sections of blades and the like. The designed axial flow pump impeller improves both the impeller lift and the cavitation resistance of an axial flow pump, facilitates computer programming, and can replace traditional similar design method and speed coefficient method of the axial flow pump to a greater extent.