Laser cleaning machine is to use the high energy and high concentration of the laser to irradiate the workpiece to be processed, so that the substrate surface attachments (dirt, oxide scale, rust, organic coating, etc.) absorb the laser energy, melt, vaporize, volatilize, It is heated and expanded instantly and is driven away from the surface of the substrate by the steam, so as to achieve the purpose of purifying the surface of the substrate.