In order to meet the requirements of high-precision, low-damage, low-stress assembly performance and technical indicators of the composite main bearing structure of the new-generation large aircraft, this paper takes the coupling analysis and control of various key features of the product as the design clue, takes the engineering application research as the main line, and systematically expounds the digital high-performance assembly coordination technical system with key feature identification, tolerance simulation analysis, deformation prediction in assembly process, preassembly analysis of measured data and high-precision assembly compensation as the main technical paths. Taking the assembly of a typical composite outer wing box as the object, the above method is applied to a complete whole-process engineering application research and experimental verification, which solves the problems of assembly coordination and product compensation  trategy design of the composite outer wing box components. The product assembly quality meets the design requirements.