For the system of a large-area laser projection image exposure using 351nm XeF excimer, its constitution, optical design parameters, and manufacturing process are introduced. The system is capable of patterning in photoresists for large-format products, with feature sizes ranging from 10 µm to below 1µm and substrate sizes ranging from 100×100mm to 600×900mm. 351nm excimer is used in this system because of its capability for exposure of conventional photoresists. Large-area lithography refers to the patterning on such areas with the desired resolution and seamless scanning. Along with the demands for lithography equipment that can provide high-resolution imaging capability, high-precision alignment performance and lower manufacturing costs, it is important for us to design and manufacture such equipment. Some key problems such as laser illumination optics, projection optics, positioning and controlling machinery, are described here. The existing problem and solutions in the optics and machinery are analyzed and discussed.