Abstract: The design of airborne radar should meet the strength and lightweight requirements. In this paper, an antenna pedestal of airborne radar is optimized based on topology optimization method, with the volume minimization as design aim, the unit density as design variable and the node displacement limit as constraint. Comparing the optimized design with original one shows that the weight of the structure is reduced and at the same time the rigidity of the structure is obviously improved. This also shows that the topology optimization method is very suitable for the structure design of airborne radar especially the antenna pedestal.