The optimization design of vortex pump impeller parameter was done by using the orthogonal design method. Orthogonal scheme of five factors and two levels was designed, and the influence of geometrical parameters on the characteristics was studied. Reynolds averaged Navier—Stokes method was adopted to simulate every set of parameters obtained by the orthogonal design method. Optimal scheme of the characteristics was found by analyzing the contrast of performance curves. The influence orders of geometrical parameters to the characteristics were obtained with range analysis. The optimization parameter combination was obtained with comprehensive balance analysis and comparison to the data result. Meanwhile, the optimized design scheme was determined, and corresponding test was carried out. It demonstrated that the experimental purpose was reached, the design method was reasonable, and it had the property of both high efficiency and non-overload.