The technique, method and workflow of building 3D model through the use of 3D laser scanning system to acquire point cloud data are presented. The point cloud data acquirement process and the combination of RiSCAN PRO software and Geomagic Studio software to build 3D model are discussed. The original measurement data (noise elimination, smoothing, data registration, target object extraction and so on) are processed to get the exact and full facet information of the target, and then a triangular mesh model is built for the target. Finally, through texture mapping done by using photos taken in the data acquirement process, the real 3D model of the target object is got. The experiment shows that the point cloud acquired by 3D laser scanning system can be effectively dealt with and the 3D model can be achieved via the technique mentioned above.