A multidisciplinary design optimization method based on CFD/CSD (computational fluid dynamics/computational structure dynamics) coupling was built. The structural performance was predicted by the structural finite element equation

and the aerodynamic loads was predicted by solving N-S equations to get reliable optimization results. Surrogate model was adopted to alleviate the huge expense caused by high-fidelity models. RBF (radial basis function) was utilized to exchange data between fluid and structure

and energy conservation principle is guaranteed. Typical wing-body configuration was optimized by the proposed design optimization method to improve the aerodynamic and structural performance. After optimization

the drag and mass of the aircraft are reduced by 5.0% and 4.2%

respectively

and all the constraints are satisfied. All these indicate the effectiveness of the proposed method.