In order to explore an effective method to improve the hump characteristics of an axial flow pump, numerical simulation of end-wall jet was carried out for an axial flow pump. The effects of injection angle, circumferential coverage ratio and throat height on the performance of the axial flow pump were analyzed, and the improvement mechanism of end-wall jet on the hump characteristics of the axial flow pump was revealed in combination with full-channel unsteady numerical simulation. The results show that the end-wall jet can effectively suppress the hump phenomenon of the axial flow pump. Under the optimal end-wall jet parameters, the lift in the hump area of the axial flow pump is increased by 64.46%, and the efficiency in the design condition is increased by 2.05%. The mechanism analysis shows that the end-wall jet can effectively inhibit the formation and development of tip leakage vortex, reduce the pressure fluctuation caused by unsteady flow such as tip reflux, and greatly eliminate tip clog in hump condition. Thus, the axial flow pump efficiency is improved while the stable operating range is expanded.