The selection of impeller of axial flow pump has a direct impact on the flow, head, and efficiency of the pump device; whether the impeller matches the actual working conditions of the axial flow pump device is the most important part as far as the design and energy saving are concerned. The improper selection could result in deviation of operating conditions of pump, the reduction of service efficiency, and the increase of unit vibration; consequently further influenced the efficiency, safety and stable operation of the pump station. Thus it is of great significance to choose a proper type of impeller for the operation of axial flow pump. Based on the vertical axial flow pump model test, the method of selection of pump impeller was analyzed; on the basis of the traditional method, the method with reference to the weighted average flow rate, weighted average efficiency and weighted average NPSH of the pump station was added. Finally, test program 3 was chosen: the blade placement angle was 6°, the flow rate was 398.5L/s, the head was 6.07m, the efficiency was 75.5%, the NPSH was 7.4m, the performance was the optimal at design points, the high efficiency area was wide, the weighted average flow rate was 414.25L/s, the weighted efficiency was 71.385%, the weighted average NPSH was 8.435m, and the overall performance was the best. The chosen program 3, given the guaranteed design parameters of the pump device, can give full play to the pump more effectively and generate greater economic and social benefits, thus providing reference for future similar projects.