In order to reduce fish mortality during passage through the large and medium-sized pumping station and maintain the balance of the ecological system, a blade strike model applied to axial-flow pump was analyzed to predict the fish passage capacity of the original pump, including blade strike probability, strike mortality and fish mortality. The theoretical fish mortality of the original pump was only 68% at the design flow point. Thus, a fish-friendly pump was designed based on the original pump to reduce fish mortality and keep hydraulic performance acceptable. Furthermore, three optimization plans were done by reducing the number of blades to two, using the streamline method of nonlinear circulation distribution to design the inlet and outlet blade angles, increasing the chord length of the blade airfoil, optimizing the profile of the leading edge to spiral and thickening the leading edge. The comparison of the three optimization plans showed that the fish mortality of plans 1 and 2 was reduced by 49% on average and that of plan 3 which was better for fish to pass through the pump was reduced by 52%. Meanwhile, the flow through the pump was simulated with ANSYS-CFX, and the numerical results such as head and efficiency were compared with the experimental results to analyze the hydraulic performance. To be specific, the head of all the plans met the operating requirements at the design flow point and the efficiency of plan 2 which corrected the inlet blade angle of plan 1 was 3% lower than that of the original pump at the design flow point, while the efficiency of plan 3 which was better for fish was 5% lower. It was noted that the fish-friendly pump was effective to reduce fish mortality even with the efficiency dropping by 5%, and it can provide a basis for axial-flow pump design of agricultural irrigation works.