Abstract: Compared with traditional measurement methods, mobile scanning technology can improve the efficiency of measurement. However, point cloud data has the characteristics of large volume, high density and redundant data. During the measurement process, the scanner coverage is large and a large number of invalid point clouds are obtained. To solve this problem, a method of extracting railway line information based on multi-source point cloud data is proposed. According to the reflection intensity and geometric features of the rail point cloud, the center line of the line is extracted by the idea of differential. The dimension reduction of the rail point cloud model is processed, and the rail model is established according to the allowable error of the rail head width of the high-speed railway road rail as the convergence condition, and the plane line and longitudinal and transverse sections of the line are extracted. Based on the reflection intensity, the rail is quickly segmented, and the Dynamo programming language is used for secondary development of Revit to quickly model, which plays an important role in promoting the intelligent and visual level of railway design.

Key words: multi-source point cloud, track centerline, rail model, Dynamo, BIM