Abstract: In this paper,an efficient ray tracing algorithm based on image theory is proposed,which is based on image theory,with high computational efficiency by using database search technology.Unlike the conventional image method,our methods have two steps: direct search and reverse search.Virtual source tree is created by directing search,after creating the virtual source tree,by inversing search;it can find all valid ray-tracing paths from transmitter to receiver.The proposed method can be applied to urban 3D environments with arbitrary building layouts and heights.Finally,we chose a community to test the accuracy of our method and the predictions are in good agreement with the measurements.