Abstract: Due to composition of multipath echo, antenna pattern splits in vertical direction, after ground-based radar is disposed in specific site. Multipath propagation significantly affects the detection performance of ground-based radar in low frequency. In this paper, the theory of multipath propagation effect is discussed, and the effect on radar detection range and accuracy is analyzed quantitatively. On this basis, reflection position adjusting and dual-band functionality are designed to eliminate the multipath effect and even promote the detection range. The proposed design offers significance for ground-based radar site optimization to improve the detection performance.