Abstract: The principle of multiple echoes production is introduced,and the condition of multiple echoes happened is presented with the method for detection of multiple echoes.Some material applications of multiple echoes in the processing of forested data are developed.Before applying some filtering method,the data is firstly processed by removing the multiple echoes data which can increase the proportion of the ground points in the points set.After removing multiple echoes data,the filtering result is better than no-removing multiple echoes in the same condition.A real example is used to validate this method.