The commonly used covering material in the multi-span smart glass greenhouse is glass, which is divided into tempered glass and ordinary glass. Tempered glass forms a compressive stress on the surface of the glass through physical methods. When the glass is subjected to external forces, it will offset the surface stress, thereby increasing the bearing capacity of the glass. Tempered glass has the characteristics of high strength and toughness. And the thermal stability is very good. Tempered glass can see colored fringes through the polarizer and the edges. In the process of building glass greenhouses, we usually use toughened glass on the top. When the surface of the glass is subjected to external forces, the glass will break into small particles and will not cause harm to the human body.

From the appearance point of view, glass is divided into float glass and ultra-white glass. Ultra-clear glass is a glass with high light transmittance and very low iron content. Ultra-clear glass has less impurities and is not easy to explode. The light transmittance of ordinary glass is about 86%, while the light transmittance of ultra-white glass can reach more than 92%. Venlo glass greenhouses like the Netherlands mostly use this kind of ultra-white anti-reflective glass. Ultra-white anti-reflective glass can maximize the light required by plants in the greenhouse, improve the photosynthesis of crops, and thereby increase productivity. After the light passes through the anti-reflective glass, the sunlight is evenly irradiated in the shed, which can avoid direct sunlight to burn the crops, and there is no shadow in the shed, so that the light is more uniform. Because of the high cost of ultra-white glass, the glass used in most domestic greenhouses is ordinary tempered glass or ordinary diffuse reflection glass, which appears to the naked eye with a faint green.

In terms of specifications, glass is divided into single-layer glass and hollow glass. Insulating glass has the effects of heat insulation, heat preservation and sound insulation. It is precisely because of these characteristics that it is widely used in greenhouses around the greenhouse. Some special greenhouses will be used for aesthetics and special requirements. Coated glass, Yuhua coated glass is commonly used.