The design ability of composite structures brings large-scale design variables, which makes it difficult to optimize structures by traditional methods, the optimization design of composite laminates is also one of the key problems. From the perspective of engineering design, multiple models are arranged for laying optimization, based on the design of composite super-ply variable definition, considering the overall engineering design constraints to sizing optimization, automatic strength checking process with the laying sequence library to optimize the laying sequence, forming a set of optimization design method of composite structure with three levels of laying optimization, initial size optimization and detailed laying optimization. Taking the structural design of composite vertical tail box of an aircraft as an example, this method is used to optimize the design of composite vertical tai lbox. The results show that: the three-level optimization design method proposed in this paper is a general method applicable to the optimization design of aeronautical composite structures. It reduces the weight of the structure and shortens the development cycle.