The processes and methods of reverse engineering are presented in detail through a practical case in this paper. Point cloud acquisition, data processing and model reconstruction are the key techniques in reverse engineering. The sample’s point cloud acquired by laser scanner is processed in Geomagic, and the boundary and characteristic line are extracted simultaneity. Finally, the surfaces are constructed and modified, and the CAD model is reconstructed in NX. The research indicates that the reconstruction data by reverse engineering is an effective technique, which can bring about high quality model and improve efficiency.