It is always a hot topic to the navigation precision problem in long range flight formations, for it is difficult to ensure high navigation accuracy for every vehicle in the formation because of big cost of highly accurate Inertial Navigation System (INS). A new cooperative localization method is presented to solve the problem of the accuracy and cost for long range flight formations, in which one master vehicle is equipped with high precision INS, and the slave vehicles are equipped without INS or with low precision and inexpensive INS. The method is to change the cooperative localization problem to a target tracking problem. At first, the relative ranges and bearing angles between the slave vehicles and the master are acquired by the detector in the master vehicle and used to be the measurement information, then, an Extended Kalman Filter estimator is designed to deal with the nonlinearity from the measurement equation, at last, the location information is communicated to the slave vehicles by data link in the formation. The simulation results validate the effectiveness of the cooperative localization method.