As we all know, laser cutting machine cutting sheet metal has incomparable advantages, it is not only high cutting accuracy, smooth cross-section without burr, whether cutting thick or thin plate can achieve good results, however, these effects are related to the laser cutting machine focus control, it is the principle of focusing and achieving better imaging effect with SLR camera. The laser cutting machine takes the laser emitted from the laser and focuses it into a high power density laser beam through the optical path system. The laser beam hits the surface of the workpiece and brings the workpiece to its melting or boiling point, while a high pressure gas coaxial to the beam blows away the molten or vaporized metal. Laser cutting machine with invisible beam instead of the traditional mechanical knife, with high precision, fast cutting, not limited to cutting pattern restrictions, automatic layout to save material, smooth kerf, low processing costs, etc., will gradually improve or replace the traditional metal cutting process equipment. Laser cutting machine recycling with the relative position of the beam and the workpiece to move, the final material to form a slit, so as to achieve the purpose of cutting.