Abstract: 3D laser scanning technology can use high-speed laser to quickly obtain the three-dimensional coordinate data of the object surface. Through registration and filter of point cloud data, a point cloud model reflecting the actual construction effect can be further constructed. By comparing the point cloud model with the BIM design model, the dimensional and position deviations generated during the construction process will show up, which can further direct the subsequent construction process or design changes. Based on BIM technology and 3D laser scanning technology, this paper proposes a set of theoretical comparison methods between point cloud model and BIM model, and uses WebGL technology to realize the visualization of the comparison results.