Abstract:The differential satellite positioning system has its contribution to the precision of satellite position, but it is also hard to use and maintain. In accordance with the features of differential positioning technology, this paper firstly in traduced the principle of differential positioning technology, with the analysis of the source of positioning error, as well as the correcting effect of differential satellite for those errors. Secondly, this paper presented the assortments, methods and developing history of differential satellite system, with the detailed introduction for the methods and features of local differential system which is widely applied in weapon systems. Finally, with the elaboration of the practical application of differential system, this paper put the emphasis on the feasibility of differential positioning system in offensive weapon and defensive weapon.