Abstract: The morphing leading edge, which is featured of smooth and continuous profile of airfoil during deflection,benefits the noise abatement and aerodynamic efficiency improvement significantly. Of the morphing leading edge, the flexible skin is one of the most critical parts as it deforms to achieve and retain the target airfoils under diverse aerodynamic loads. However, due to the complex deformation mechanism and numerous factors affecting the deformation quality, the structural design of flexible skin is still difficult to achieve the high-precision shape of cruise and droop at the same time,which has a negative impact on the aerodynamic efficiency of the wings. Therefore, this paper carries out the optimization design of flexible skin structure, through the detailed analysis of deformation mechanism and the number of optimization variables, reduces the constraint range of optimization variables, and thus reduces the complexity of optimization mathematical model. For the same flexible skin model, the existing method and the presented method are used to carry out the structural design. The research results show that the proposed method can reduce the maximum displacement deviation of droop state and cruise state by 43% and 55% respectively, thus the method can be used to improve the aerodynamic efficiency of the wings.