In order to solve the problems of low efficiency, difficult data acquisition and analysis in the attitude measurement of on-board instruments, an online measurement method of product installation attitude driven by model data is proposed. By extracting the coordinate information of the prism on the target to be measured in the 3D design model of the satellite, the high-precision online measurement system is driven to realize the automatic measurement of the target installation posture in the actual measurement scene; the product assembly accuracy online measurement data management system is designed, the design and development of the precise measurement data integration interface are completed, and the online data acquisition, correlation fusion, analysis and application are realized. Taking the detection instrument on FY-4 satellite as the test object, the results show that compared with the traditional method, the precision measurement efficiency of this method is improved by 75.5%, the number of operators is greatly reduced, the operation efficiency is improved, the data traceability and quality control ability of the satellite precision measurement process are enhanced, and the application effect is good.