Abstract: In order to study the influence of the airfoil series connection on the hydraulic performance and internal flow field of the axial-flow pump, five different airfoil series solutions were designed based on the axial-flow pump model ZM25. Keeping the airfoil section at the shroud unchanged, and the center of other airfoil sections were connected in series along an oblique line, with the series stacking angles were-8°,-4°, 0°, +4° and +8°, respectively. Based on CFX, the hydraulic performance and internal flow patterns of the five schemes under different operating conditions were predicted and simulated, and the calculation results were verified and compared with the experimental measured values. The research results show that when the airfoil is connected in series by negative angle, the pump head can be improved, but the efficiency of the pump will be reduced. In addition, when the airfoil is connected by positive angle, the pump efficiency is improved, but the head is reduced. For the internal flow field of the pump, when the airfoil is connected in series by a negative angle, it can improve the pressure distribution on the back of the blade, improve the cavitation performance of the pump and the axial velocity distribution along the axis direction of the axial-flow pump, and reduce the radial flow in the pump. When the airfoils are connected in series at a positive angle, the axial-flow at the outlet of the axial-flow pump can be more uniform. The research results can provide a certain reference for the design of the axial-flow pump.