Abstract: A parameter optimization method was proposed for waterjet axial pump blade design based on the global sensitivity analysis and prediction method of surrogate model. Taking the fixed blade angles in impeller and guide vane as the optimization parameters, and taking waterjet pump efficiency and raise range as the optimization objective, the energy and cavitation performances of the axial pump were simulated and analyzed. The simulation results show that, the fixed blade angle in the impeller has a greater influence on the pump performances than that in the guide vane. The optimization method can well improve the axial pump performances, in both efficiency and cavitation performance, being suitable for the waterjet axial-pump design.