Abstract: In order to improve the practical application effect of large axial flow pumps, taking the 1800ZLB axial flow pump as an example, the optimization and structural characteristics of large axial flow pumps were simulated and analyzed. Research has found that there are significant differences in the external and internal characteristics of axial flow pumps under different blade tip and cascade density conditions. Among them, under the condition of blade tip and cascade density of scheme 4, the external and internal characteristics of axial flow pumps are the best. Moreover, under the worst-case operating conditions, the stress level and deformation of axial flow pump blades are the lowest, only 12.014 MPa and 0.047513 mm, respectively. The structural strength and stiffness meet the specified requirements, which is conducive to improving the practical application effect of large-scale axial flow pumps and providing support and reference for better industrial production activities.