Abstract BDS/INS deep integration navigation,by using INS-aided BDS acquisition and carrier tracking,has been shown to improve navigation performance under low signal-to-noise ratio and high dynamic situations. It is important to develop the research on BDS/INS deep integration navigation with application of the BDS system. In this paper, we investigate the mechanism and performance evaluation criteria in BDS/INS deep integration navigation. The deep composite structure design is given and the entire performance is simulated on a software receiver. The simulation shows that this technique is effective and useful for actual engineering applications.