Abstract: It's important to solve the drag problem of grid fin. Former studies indicated that fin with swept angle could reduce the wave drag at supersonic speed. Different method of windward swept and different swept angle of grid fins were investigated by the method of CFD, including the curve leeward gird fin. Numerical simulation results showed that windward swept grid fin could reduce the wave drag obviously, and the method of gird intersection swept performed better, the windward swept angle influenced the lift characteristics of grid fin basically, showing different effect on flow chocking modification, and the curve leeward gird fin had better performance at lift-to-drag ratio.