Against the backdrop of the rapidly developing aviation manufacturing industry, there is an increasingly urgent demand for the high-volume and high-quality delivery of aircraft landing gear doors, which are critical components for ensuring flight safety. Traditional assembly methods face numerous bottlenecks, making it difficult to meet the industry’s evolving requirements. Consequently, a design study has been conducted on the assembly units for aircraft landing gear. By analyzing the structural characteristics and assembly process flow of the landing gear doors, the assembly procedures were optimized and reorganized. A pulsatile assembly unit incorporating dual-attitude modular assembly devices, an automatic transportation system, curing devices with heating, and module storage facilities was designed. Digital simulation technology was employed to perform a simulation analysis of the assembly process, verifying the feasibility of the proposed scheme. This production addressed issues such as long curing cycles for liquid gaskets, low efficiency in layered hole-making, and difficulties in transporting modular fixtures. It achieved semi-automation and intelligence in the assembly, curing, and transportation processes of landing gear doors. Compared to the production mode during the development phase, the production cycle for individual products was reduced by 50%, and annual delivery capacity increased by 100%. The research findings provide effective technical support for achieving efficient and high-quality assembly of aircraft landing gear doors.