The performance principle of coated glass is mainly thin film optical principle. Single-layer film system is the use of certain film materials, infrared reflective properties, to achieve heat reflection function, and the use of the film itself, the visible spectrum of reflective properties, the formation of reflective color. Multi-layer film system is the use of certain film materials, infrared reflective properties at the same time, the use of film in the visible spectral range of the interference effect, through the adjustment of the thickness of the film, both to achieve the function of heat reflection and the formation of the desired reflection color.