Abstract: The EMD filtering method based on the cross-validation is developed and applied to the study on GPS multipath effects.Experiments with both simulated data and real GPS observations show that the method can select the signals in the IMFs,reduce random error and separate noise from signals adaptively.Using this method to extract and model the correction of Multipath error can weaken the effects of Multipath,and then improve the accuracy of GPS surveying in dynamic deformation monitoring.