Abstract:In view of the problems of low data acquisition efficiency, difficulty in field operation and low detection accuracy in traditional size inspection of steel structure bridges, using the characteristics of 3D laser scanning technology ,a steel plate composite beam based on 3D laser point cloud data is designed. Non-destructive testing method for the size of multiple parts of components. The main steps include scanning design, point cloud acquisition, point cloud data preprocessing and registration, cross-section acquisition and size detection. Taking the steel plate composite beam structure inspection work of a highway bridge project as an example, and compares the traditional size inspection method with the method introduced in this article. The experimental results show that the method introduced has the advantages of non-contact measurement, high reliability and comprehensive detection range.