Abstract: The problem of multi-sensor detecting and multi-target tracking was mainly studied. Firstly, the observability was analyzed according to the detecting geometry of double satellite, and the state equations and measurement equations were established according to the turning model based on gravity. Secondly, for the problem that fight path tracking abnormity exists in the situation of tracking multi-target, the SME filter algorithm based on binary polynomial was raised. Finally, in order to improve the tracking accuracy, the improved UKF algorithm based on the iteration was raised. The simulation indicates that all targets can be well tracked with the BPGM-SME algorithm. Compared with UKF algorithm, the improved UKF algorithm can get better convergence effect, and the tracking accuracy is better.