Abstract: Aiming at the machining requirements of multi-variety, small-batch and large-sized parts in the aerospace industry, a design scheme of flexible automated production line based on large-sized five-axis machine tools is proposed. Taking pallets as carriers, the production line integrates modules including heavy-duty RGV transport mechanism, ground rails, loading/unloading stations and buffer stations to form a flexible automated manufacturing system. A double-layer bidirectional telescopic RGV structure is adopted to realize the layout on both sides of large-scale machine tools without intermediate exchange stations, which reduces floor space occupation. This paper elaborates on the modular design method for independent development and system integration of each functional unit. Precise mechanical calculation and type selection verification are carried out for the key moving components of the RGV. Verified by the overall design and practical application of the flexible line, the production line can meet the machining requirements of aerospace components.