Multipath is the key factor which affects communication, navigation system performance. It not only affects the signal power, but also causes time delay, frequency shift and polarization parameters changing, resulting in a decrease in the communication and navigation system. To solve this problem, the fast reverse ray tracing algorithm based on virtual source tree, partition, backward detection, was proposed to predict multipath signal loss and delay distribution accurately. Besides, the urban scenes were taken as examples to show the algorithm of signal multipath transmission, and the diffraction algorithm was studied to improve the accuracy of the prediction. Taking the signal propagation through simplified street models for example, the consistency of reflection path and power distribution can be proved by comparing with the MATLAB program based on the proposed algorithm and the simulation from using Wireless Insite software, in which way, the validity of the algorithm was also verified.