To solve the aileron reversal problem in aircraft design, an aero-elastic tailo ring optimization model of composite wing for engineering requirement was establ i shed and the Pareto genetic algorithm (PGA) based on Pareto optimal set was developed. In order to obtain the Pareto optimal set, the Pareto filtering pool was constructed based on weight information in PGA. And the niche techn ology was utilized to keep the diversity of population. The computation of the t e st function indicates that PGA has good convergence. In the numerical example, s etting the lifting coefficient and the rolling moment coefficient as objective f unctions, the expected Pareto optimal set was obtained by using PGA. The re sults show that the Pareto optimal set satisfies the engineering requirement and can provide many feasible projects for the decision-maker to choose.