Abstract: According to the existing conditions of space-based navigating and positioning system and the precision orbit requirements of our country for LEO and MEO,the orbit determination principle based on information fusion was addressed. By introducing the prior information of satellite state parameters to be estimated,a method of information fusion for satellite orbit determination based on Bayes statistics model was presented,which added the observation noises into the linearized fusion model of observation equations,and then used the probability estimation fusion model to obtain the MAP(maximum aposteriori probability) of satellite states by Bayes theory,moreover,the orbit determination precision was analyzed.In addition,the fusion coefficients of multi-information were given based on the minimization of variance of desired fusion satellite states.Finally,through the simulation calculations and analysis for the distance data and velocity data integrative fusion strategy used for orbit determination based on combined measurement and control system,it indicates that this fusion method is more feasible and efficient.