Abstract: Based on the technical requirements of engineering design projects, R&D design and engineering construction experience, this paper analyzes and summarizes the principle and structure of CATR reflective surface back frame structure in precision installation and positioning engineering. Firstly, the general technical requirements and general installation process route of the precision positioning and installation of the CATR reflective surface are summarized; combined with the engineering cases and implementation processes of the real project, and based on the analysis of the precise measurement data of the spatial position error, the whole process of the precision positioning and installation process of the CATR reflective surface is sorted out, so as to provide guidance and reference information for the precise installation and positioning of the CATR reflective surface in the future.