In order to solve the cycle slip problem for double difference observation sequence in Beidou satellite navigation system, wavelet transform combineda sliding window linear interpolation method is proposed. Using wavelet transform to scale the carrier phase detection sequence to extract high-frequency coefficients. The singular value of the high frequency coefficient can be obtainedat the cycle slip,then replacing singular values with sliding window bilinear interpolation, and coefficient reconstruction is performed. The cycle slip can be repaired better. The experiment uses this method to simultaneously repair the first and second layers high-frequency coefficients and to repair only the first-layer high-frequency coefficients. The results show that the number of repairs of the first and second layers simultaneously is less and higher repair efficiency.