Composite materials are widely used in industries such as aerospace, wind power, and marine, because they have higher strength and stiffness than metal materials and have high fatigue strength due to their high specific strength and non-stiffness. The dynamic response optimization method which considers the dynamic loads on the composite structure is quite complicated and takes a long time to solve. In the existing dynamic system optimization, the dynamic load was multiplied by the dynamic coefficient to obtain the static load, and then the optimization was performed under the linear static condition. In this study, optimization was carried out using the equivalent load method (ESLM) for the nonlinear optimum design of composite structures with dynamic loading. ESLM is an optimization technique that can obtain the same response as nonlinear transient response analysis through linear static analysis, and can express the behavior of the structure under dynamic load differently from the method using the dynamic coefficient. In addition, optimization is performed by static analysis, which greatly reduces computational cost and time compared to dynamic response optimization. In this paper, the optimization of unidirectional laminated composite structures using ESLM is studied. In addition, the accuracy of the optimization results and the efficiency of the calculation using ESLM are verified compared with the existing FDM optimization.