The proposed morphological filtering algorithm improves the filtering effect of the radar point cloud greatly. Separation accurate and efficient for the ground points and non-ground points has always been the key problem to the filtering algorithm. Many scholars focus on the determination of the filtering threshold. The contour is an important research content in spatial analysis. Based on the progressive morphology filtering algorithm, the contour is used to obtain the key threshold of the filtering algorithm quickly. Comparing with the traditional manual testing threshold, the contour threshold determination method is more intuitive, and the appropriate threshold can be determined relatively quickly. In order to test the filtering efficiency and accuracy of the contour-morphological filtering algorithm, this paper uses the progressive triangulation filtering algorithm for comparing purpose, and the advantages of the proposed algorithm have been proved.