The optimal design of a new double-chamber airbag impact attenuation system for landing equipment was addressed. The design methodology involved the multidisciplinary design optimization technology and the combinatorial optimization strategy based on the commercial software of ISIGHT, HYPERMESH, LS-DYNA and a program by FORTRAN code. The optimization objective was the airbag volume. The constraint conditions included the height and the initial pressure of the above chamber, the height, initial pressure, venting pressure, venting area, bottom area of the under chamber, the overload and the smallest distance from the ground of the landing equipment. The results showed that the airbag reached the minimum volume based on the multi-disciplinary design optimization method, and the overload and the smallest distance from the ground of the landing equipment met the design requirements. The multi-disciplinary optimization design is feasible for design of airbag to cut down development cost by reducing the design cycle and the number of tests.