Abstract：Taking airborne LiDAR laser point cloud data and high resolution aerial image as data source,aiming at the spatial distribution characteristics of the building(structure) of the railway,a region growing segmentation algorithm was proposed for the top surface of building based on vector analysis and curvature calculation.It was established the methods of the building contour line extraction,regularization and readjustment,and realized 3D modeling of building and structure affiliated railway.Based on point cloud built(structure) surface segmentation,the technical flow of 3D modeling of railway construction(structure) is established.It provides reliable technical and service support for survey and design,line transformation,asset inventory,emergency rescue and 3D digital railway construction.

Keyword：airborne LiDAR;building and structure affiliated railway;region growing segmentation algorithm;top surface contour line;regularization;