Abstract：This paper is concerned with the sidereal day repeat characteristics of the multipath error and high frequency random noise of calculated coordinates for real-time deformation monitoring. First, we apply the EMD and EMD combined with wavelet threshold de-noising methods, to the existing coordinates multipath time series model. Then, based on this model and through sidereal filtering, we weaken the multipath error of subsequent coordinates, which has a strong correlation with the model. The measured data processing results show that the EMD method can remove the high frequency random noise sequence and weaken the effect of multipath error of GPS/BDS real-time monitoring effectively, improving by 50% the accuracy of real-time monitoring. The EMD and wavelet combined method is superior to single EMD filtering method.