Abstract: The optimization design of composite stiffened panel can be difficult to carry out due to its innate features such as anisotropy,complex interfaces and multivariate design etc. In this paper,a hierarchical progressive optimum design method is proposed,where the side composite stiffened panel of superstructure is selected as the research object. Firstly,all available design variables are extracted according to actual engineering practices and the design characteristics of composite stiffened panels. Then,calculation and analysis for the two-stage optimization are conducted on the stiffened panel by investigating the sensitivity of all design variables. Finally,a comparison of results before and after the optimization shows that the hierarchical progressive optimum design method effectively solves the multivariate design problems of complex composite stiffened structures.