As a two-dimensional scanning device, galvanometer can be used to image surface damage status of different regions into CCD. The galvanometer scanning method can accomplish surface damage inspection of large-aperture optical elements without moving optical elements or imaging devices. A damage inspection method for large-aperture optical elements based on galvanometer scanning is presented. The experiment is conducted based on the galvanometer scanning method. By setting reference points on the optical element surface, the damage size and location are obtained after scanning steps and image processing. Then, the results are compared with those from microscope. The resolution of the inspection system is (2.08±0.015) μm/pixel, and the inspection range is larger than 2.5 cm. The inspection accuracies in the horizontal and vertical directions are 3.76% and 1.37%, respectively. The inspection accuracy of damage size is 6.19%. It demonstrates that the galvanometer scanning damage inspection method can detect the damage status on the large-aperture optical element surface with high accuracy.