At present, the research of road extraction using vehicle-borne point cloud mainly focuses on structured roads with regular road cuts.However, some roads in reality are flanked by grass, and the extraction method of structured roads is no longer applicable.To address this problem, an automatic road surface extraction method integrating the moving window height difference and neighboring point serial number difference is proposed.First, the adjacent point space is used to realize the extraction of scan lines, and the road boundary points are extracted according to the moving window height difference as well as the adjacent point serial number difference.Next, the road boundary points are fitted with RANSAC algorithm.Afterwards, the road surface point cloud is extracted according to the linear programming principle and filter processing.Finally, two sets of road data are used to test the proposed method.The completeness of road surface extraction is 99.79% and 99.52%, the correctness is 99.91% and 99.62%, and the quality is 99.70% and 99.15%, for the two datasets respectively.The experimental results show that the proposed method is applicable for road surface extraction of structured road and unstructured road with grass on the roadside.