Many vegetable farmers in the use of thermal insulation in the insulation and antifreeze effect of the situation is not good, summarized as follows: First, the greenhouse insulation efficiency is not good. Some vegetable farmers who have built plastic greenhouses report that during the day when there is sunlight, the temperature in the shed warms quickly, the effect of warming is good, and the temperature drops quickly after nightfall. After zero hours, it is almost the same as the temperature outside the shed; The warming effect during the day is also not good. This is a normal phenomenon because the large, medium and small sheds built are all greenhouses that use sunlight as their source of energy. The source of warming heat is mainly taken from sunlight, and the cover is only one thin film, so after the sun goes down, The temperature in the shed will gradually decrease to 1-2°C higher than the temperature outside the shed as the temperature outside the shed decreases. Under the cold wave without sunshine for several days, the temperature inside the shed was almost the same as that outside the shed. The solution is: 1, stamped with a layer of film. 2, covered with a layer of shade net. 3. When the cold wave comes, cover the straw. The above three kinds of measures can slow down the spread of heat inside the shed, improve the insulation effect, and increase the temperature in the shed at night and under continuous weather conditions by 3-5°C. Second, frost occurs under the conditions of the insulation facilities. Some vegetable farmers have reported that within the protection scope of the wind barrier, even frosty phenomena occur in plastic greenhouses, causing some cold-resistant vegetables such as cauliflower and lettuce to be subjected to frost damage. This is due to the decrease in surface air temperature. Under normal circumstances, only frosted leaf parts and growing points of lettuce are frozen, and cauliflower's fresh cauliflower is damaged. The solution is: 1, plastic greenhouses with the three methods described in the previous solution. 2. The surface of the wind barrier and the surface without insulation facilities can lay a layer of film or shade net on the night before the frost falls. 3, the use of old newspapers, old paper bags, plastic bags, sacks, rags cover also have a protective effect. Third, what kind of plastic film is better. At present, there are many kinds of plastic shed films sold on the market. The shed films used in the sheds in China mainly include polythene common shed films, ethylene-acetate vinyl copolymer shed films and special functional new shed films. Special functional films include PE longevity film, PE longevity drop-free film, diffuse reflection film, and light conversion film. It is better to use PE multifunctional film and diffuse reflection film. The former is a three-layer film with a variety of special functional auxiliaries added to the raw materials of polythene common film, in addition to the advantages of longevity, good heat preservation effect, etc., it can also reduce the humidity inside the greenhouse and reduce the diseases of vegetables. The latter is based on a polyethylene-based resin that incorporates a certain percentage of diffusely reflective nuclei. The film has direct light converted into scattered light, so that the light distribution within the studio, the temperature, light changes more stable, reducing the high temperature on the vegetables at noon and other special features such as damage. The insulation effect at night is also better.