Aiming at the problem that the blade type and energy loss of the vortex pump cause the whole machine efficiency to decline seriously, the model 150WX-200-20 vortex pump was taken as the research object, and the hydraulic and structural design of the vortex pump was carried out. The three-dimensional models of the forward-curved (R1-F2) and the backward-curved (F1-R2) blades were established by using Pro/E of three-dimensional design software. In this process, six groups of forward-curved (R1-F2) and backward-curved (F1-R2) blades were designed as control group. CFD of fluid calculation software was used for numerical calculation. Taking two kinds of blade deflecting as breakthrough point, combined with inlet and outlet velocity triangle of blade, the work process and energy loss process of different impellers of vortex pump were compared and analyzed. The energy loss transfer and transformation mechanism under these two different impeller types can be found. It was found that for the efficiency of vortex pump, the efficiency of forward-curved impeller was higher than that of backward-curved impeller before the design flow point, and after the design flow point, the efficiency of backward-curved impeller was higher than that of forward-curved impeller. For two different types of impellers, before the design flow point, the forward-curved blade had stronger function and less energy loss;after the design flow point, the backward-curved blade had stronger function and less energy loss. It was of great significance to the national agricultural development, and it had a certain reference value for the selection of the blade of vortex pump in the future.