1090ES Automatic Dependent Surveillance-Broadcast (ADS-B) is a surveillance mode recommended by the International Civil Aviation Organization (ICAO). The algorithm mechanism of CPR encoding and decoding to the target aircraft position is presented by the ADS-B. The process of messages receiving and sending is simulated, and the receiving and sending data is counted. Meanwhile, an ADS-B receiving model is established to simulate the influence on successful receiving ADS-B message when the mode A/C and mode S interferences in Second Surveillance Radar (SSR).The results show that the CPR algorithm has the high validity and accuracy to the encoding and decoding of target aircraft position message, and that the reduction of co-channel interferences and decrease of the distance between target aircraft and local aircraft can effectively improve the probability of successful receiving ADS-B message.