Abstract: Due to the influence of observation error and sampling rate, the cycle slip cannot be accurately detected by Doppler integral method and polynomial fitting method during cycle slip detection and repair. An improved cycle slip detection method based on generalized extended extrapolation Doppler is proposed by mining the prior information of the latest Doppler data and the influence of the latest data, the generalized extended extrapolation model is used to obtain a stable Doppler extrapolation value with high precision, and then the Doppler extrapolation value with high precision is used to detect the cycle skip with the carrier phase. Finally, the detection value is obtained by the way of one difference The cycle slip detection is carried out on the measured data. The results show that the improved cycle slip detection method with generalized extended extrapolated Doppler can accurately detect the cycle slip of 1 week or more, and its performance is better than that of Doppler integral method and polynomial fitting method.