Aiming at the problem of low automation and low efficiency of traditional aircraft assembly line, a modular flexible aircraft assembly line is designed. Plan the traditional parts assembly line and general assembly line as an assembly line. Modularize the general assembly area, the component assembly area and the parts assembly area according to the assembly process and the nearly layout principle. Design of assembly tooling, hole equipment and working platform of assembly line is modular. Set up common mobile interface and energy information interface. Through the analysis of the efficiency of the aircraft assembly line, it is concluded that: On the basis of not increase the construction cost significantly, the equipment utilization rate of the modular flexible aircraft assembly line has been greatly improved, the overall automation degree has been significantly improved, and the assembly cycle has been significantly shortened.