To resolve the problems like high coupling,low computation efficiency and hard to obtain the optimal solution features with designers'preferences,a new approach for multidisciplinary design optimization(MDO)and multi-objective design optimization(MODO)based on physical programming and improved collaborative optimization was proposed.The basic ideas and optimization process were presented.Closely combined with the practical engineering experiences,the MODO problems was transformed to comprehensive objective design optimization problem,featuring with designers'preferences.Then,multi-level optimization model was constructed by improved collaborative optimization strategy so that the optimal solution featuring with designers'preference was obtained.Finally,taking the absorber of aircraft landing gear as example,the proposed method was proved to resolve the non-inferior solution of MODO effectively.