In this paper, GPS measurement technology, Encke method to solve satellite orbit perturbation and generalized Kalman filtering technology are organically combined together, and an innovative solution— carrier phase & pseudorange integrated dynamic orbit determination (CPPIDOD) for low earth orbit spacecraft on-board autonomous precise navigation and positioning using GPS is presented. Difficult problems of dynamically resolving of integer ambiguities and amendment of cycle slips in the application of GPS carrier phase have been solved. Based on all these, technique of carrier phase & pseudorange integrated dynamic differential relative navigation between two spacecrafts is brought forward. Results of numerical simulation analyses and semi-physical simulation tests show that the solutions presented in this paper are feasible. They can significantly improve the performance of GPS positioning, and their models, algorithms and software are practical for engineering use.