Based on the system of a large-area laser projection imaging lithography using 351 nm XeF excimer laser, some optical properties of the system including illumination system and folded projection system are measured. According to the variation of energy and beam quality of the beam passing through two cylindrical square lenses and two microlens arrays and projection folded system, some evaluating norm about excimer laser beam uniformity is partly adopted to evaluate this optical system. The energy distribution on different crucial areas of the optical system and the top-hat factor can be obtained. The results show that the microlens array maintains the beam uniformity, whereas the energy utilization rate is suppressed due to the diffraction. Meanwhile, through the printed circuit board (PCB) and ITO lithographic experiment, it shows that the designed double-telecentric confocal projection lithographic system can meet the required resolution, provided the uniform-output energy is controlled to be in accord with the exposure dose.