Abstract: In order to to improve the practical application performance of large axial flow pumps, the 1800ZLB axial flow pump is taken as the research object to conduct simulation analysis on its optimization and structural characteristics. 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 most severe operating conditions, the blade stress and deformation of the axial flow pump reach the minimum values of 12.014 MPa and 0.047513 mm respectively. The structural strength and stiffness fully meet the specified engineering requirements, which is conducive to effectively improving the practical application effect of large-scale axial flow pumps and providing theoretical support and technical reference for better industrial production activities.