Abstract: BeiDou Navigation Satellite System (BDS) has yet to meet the needs of global navigation and positioning as the satellite tracking and the geometry of reference station are not precise.These situations influence the accuracy of satellite orbit determination. In view of these problems, based on dynamic orbit determination theory and methods, the analytical contribution value of multi-GNSS combined orbit determination was applied to improve the precision of parameter solutions.Using measured data, the statistical contribution values of BDS/GPS combined orbit determination to the solution precision of orbit and clock error was analyzed. Results show that the contribution of combined orbit determination to the solution precision of common parameters shared by different systems is significant. The solution precision for orbit and clock error was significantly improved except in the case of GEO satellites. The statistical contribution values of BDS/GPS combined orbit determination to the precision of BDS satellite orbit, the RMS of BDS satellite clock error and the RMS of receiver clock error were 36.21%, 26.88% and 20.88% respectively. The contribution of receivers in areas with few visible satellites to the clock error was particularly significant, the contribution value is 45.95%.