Thermal paper roll is a kind of printing paper especially used for the hot-sensitive printer. Its quality directly affects the printing quality and storage time and even affects the service life of the printer. The thermal sensitive silver paper is generally divided into three layers, the bottom layer is the paper base, the second layer is the thermally sensitive coating, the third layer is the protective layer, mainly affecting its quality is the thermally sensitive coating or protective layer. If the coating of heat-sensitive cashier paper is not uniform, the color of printing will be different when printing. If the chemical formula of the coating on the heat-sensitive cashier paper is not reasonable, the preservation time of the heat-sensitive cashier paper after printing will be shortened. The protective layer is also crucial for the preservation time after printing.