The higher-order statistics method is applied to processing the earthquake tidal deformation observation data.The tidal deformation observation data of Tai′an seismic station before the ML4.6 earthquake in the boundary region of Puyang and Xinxian counties on April 9,2006,are processed and analyzed.In the period of time before the earthquake,intervention of abnormal signal is found.On low point of the results has guiding significance to seismic anomaly information extraction.This method can extract some short-impending anomalies of seismic tidal.