Based on 150 seats BWB civil aircraft, an aluminum triple-bubble cabin model are built. By large deformation analysis, the triple-bubble cabin is indicated the bending stress theory of non-cylindrical fuselage in the internal pressure. Zero-order parameter optimization arithmetic is employed to optimize the sizes of skin, stringers, beams and ribs in the triple-bubble cabin. By restricting the maximum stress and deformation, a light triple-bubble cabin configuration is obtained. The structural analysis method on the aluminum triple-bubble cabin is reliable and applicable.