Abstract: Cycle slips often occur in carrier phase observations due to the problem of the obstruction, low signal-to-noise ratio, or high receiver dynamics. An effective INS(inertial navigation system)-aided cycle slip detection and repair method is presented, which is based on PPP/INS integrated system. It utilizes high-precision INS information instead of a pseudorange to remove the satellite-receiver geometric range in the wide-lane and ionospheric-free phase combinations, cooperates with satellite and epoch differential processing, and creates INS-aided wide-lane model and INS-aided ionospheric-free model. The INS-aided ionospheric-free model is unaffected by the dramatic changes in the ionosphere but cannot detect the special pairs of cycle slips. The INS-aided wide-lane model has a long wavelength. However, it is insensitive to the equal cycle slips on dual frequencies. So their combination can achieve mutual complementary advantages. The results show that this method can effectively detect and repair various types of cycle slips. Moreover, when it comes to the cycle slip after a GPS interruption, the method can realize the instantaneous correction.