This field mirror is a 30 spot welding field mirror, the material is K9 glass, the field mirror is to focus the collimated laser east on one point, improve the energy density of the laser beam, the use of laser high energy to the material for a variety of cutting, marking, welding, cleaning and surface treatment and other materials processing, while when the direction of the incident laser beam changes, The field mirror can still maintain the relative size and energy density of the same spot, so that the laser beam can be processed at different material positions. The combination of the field mirror and the galvanometer, which can quickly and accurately change the direction of the laser beam, can realize the high-speed and precise machining and processing of materials.