Abstract: According to the blade design requirements,this study considers the stability of the airfoil design performance to the leadingedge roughness and proposes specific indicators to represent its sensitivity,and then improves the optimization model of the thick wind turbine airfoils with low sensitivity to leading-edge surface roughness. Integrated with the airfoil geometrical design method,performance calculation method and the optimization algorithm,an optimization design method to reduce the aerodynamic performance sensitivity to surface roughness is established. A case design of a 35-percent relative thickness airfoil is performed and the results show that the newly proposed method can improve the airfoil design performance under clean surface condition and effectively decrease the loss in the airfoil performance of leading-edge surface roughness.