Abstract: Ultra-light-weight sandwich metal structure characterized by cells has special combination of physial property and mechanical property, such as the combination of light-weight and high specific strength. It is becoming the hotspot of current research. The requirement of light-weight makes the aluminum foam with higher specific strength and specific stiffness the important development direction. In this paper, the application technologies of sandwich structure with closed-cell aluminium foam are studied. The manufacture solution of the fixing-board of an antenna using the sandwich structure as a replacement of aluminium alloy 7075 is obtained. 54% weight reduction of the fixing-board is realized while satisfying its mechanical property.