Abstract: A multi-objective optimization model for the design of stratosphere airships is proposed, which aims at minimizing the drag force and the weight, whilst maximizing the ultimate strength and stiffness of airships. SPEA (Strength Pareto Evolutionary Algorithm) method is used for the multi-objective optimization design. SNR (Signal-to-Noise Ratio)-based decision method is applied to determine the final design from the Pareto solution set derived from the optimization computation. This study demonstrates that the application of the SPEA method is effective and efficient in obtaining the Pareto surface with uniform non-inferior solutions. Based on the SNR-based decision method, the optimal design solution, which satisfies the actual needs, can be efficiently identified from the non-inferior solution set.