The design and optimization of axial-flow pump blades usually takes the hydraulic design as the principle, then takes strength check into consideration. That cannot achieve the goal of integrated optimization. The mathematical model of axial flow blades of multidisciplinary design optimization was established on the basis of the subject analysis and the coupling relation between hydraulic and structure subject. The mathematical model could achieve the targets of the highest efficiency of impeller and the lightest weight of blades by using collaborative optimization algorithm. The study shows that multidisciplinary design optimization could improve the overall performance of axial flow blades, which also meet the requirements that the axial is efficient and lightweight. The collaborative optimization algorithm for axial flow blades model of multidisciplinary design optimization is efficient and feasible.