Abstract: Focusing on the target RCS fluctuating sharply in incident angle, this paper proposes a CFAR Detection Algorithm for Multisite Radar with unknown target SNR Information. Because target’s RCS is fluctuating and unknown sharp in incident angle, we cannot apply conservation Bayes fusion detection method directly because of unknown SNR of any radars’ receive signal. This method is a fusion way which finish the total CFAR detection by the test statistic of each radar’s receiving signal without SNR information. Then we design a detection method with adaptive threshold that is gained by other radar’s receiving signal test statistic. Simulation results illustrate that a detection performance closing the known SNR information is obtained by the proposed algorithm.