Abstract: Traditional steel structure deformation detection mostly relies on total stations for prism-free measurement. By collecting three-dimensional coordinates of feature points in the deformed area and analyzing their geometric relationship with the reference plane, the deformation can be calculated. Although this method can meet basic accuracy requirements, it has limitations such as low efficiency of single-point measurement and inability to fully capture the structural surface information. This paper systematically discusses the applicability of three-dimensional scanning and holography technology in steel structure deformation monitoring. By scanning the building surface, high-density point cloud data can truly restore the overall shape of the structure, enabling overall deformation monitoring and trend prediction. Combined with experimental simulations, the feasibility and superiority of the two technologies in deformation detection and dynamic positioning are verified.