Abstract：On the basis of the reconstructed single difference residual of carrier phase, we estimate the multipath repetition time of Beidou satellite by using the segmentation idea; we then extract the multipath of single difference residual of carrier phase by regularization method and classical wavelet filtering method respectively to obtain a “clean” single difference residual sequence. The experimental results show that Tikhonov regularization is feasible to correctly extract the multipath signal, the multipath signal is smoother than the original residual measurement, and the estimation method of the regularization parameter is further optimized. After using the optimized Tikhonov regularization method and sidereal filtering, the single difference residual of carrier phase is improved by 40.5% on average. The coordinate residual in E, N and U directions are improved by 24.8%, 26.3% and 42.7%, respectively. The optimized Tikhonov regularization is superior to the traditional wavelet filtering method in both the observation and coordinate domains.