With increasing applications of SPF/DB structural components in the fields of aeronautics and astronautics, a large amount of new products are researched and developed. The traditional manufacture mode depending on experiences can not satisfy the new requirements. In this paper, a method of structure optimization design and manufacturing for multilayer load-carrying parts is proposed. Based on the given outlines of the components and the characteristics of SPF/DB process, the form of internal hollow structures are designed and modeled by CAE software before forming and the result of calculating is used to direct the SPF/DB process. It is verified that the optimized structure can satisfy the requirements of strength, stiffness, light weight of parts, which agrees well with the results of simulation. And it is also showed that this method is effective to decrease the quantity of tests, shorten the development cycle and reduce the development costs.