Straw mats are the earliest and most widely used thermal insulation quilts in production. First, it uses local materials and makes use of surplus agricultural products in rural areas. Secondly, the price is cheap and the thermal insulation performance is good, so grass has become an irreplaceable thermal insulation material for the front roof in the thermal insulation quilt of solar greenhouse. However, with the large-scale development of solar greenhouse, the supply of grass is becoming more and more tight, and grass itself does have its insurmountable shortcomings: heavy weight, long storage time, high labor intensity, and it is difficult to realize mechanized operation; The waterproof performance is poor, and the thermal conductivity of the material increases sharply after meeting water, almost losing the thermal insulation effect, and the weight doubles, which causes great pressure on the greenhouse skeleton; In windy areas or windy conditions, its thermal insulation performance is limited if it is not used in conjunction with other sealing materials because of its many pores. Therefore, the research and experiment to explore the use of new covering materials have not been interrupted. Paper quilt is the earliest insulation quilt material used with grass. The source of paper quilt is mainly old cement bags, and now it has been developed to order directly from paper mills, but the cost of the latter is much higher than the former. The paper quilt is mainly laid under the thatch to prevent the thatch from cutting the plastic film, and a dense thermal insulation layer is formed between the thatch and the plastic film, which further improves the thermal insulation performance of the greenhouse. According to the measurement, in cold winter, using 4-6 layers of 5 cm thick old cement bag paper can increase the indoor temperature of greenhouse by 7℃ to 8℃. However, paper quilts, like grass, have a sharp decline in thermal insulation after being soaked in rain and snow, and are easy to be damaged. If a layer of straw mats or some reeds are added to the surface of the paper quilt to make it look like straw mats, the heat preservation effect will remain unchanged and it will not be damaged easily. Quilt is the first thermal insulation material used in cotton or non-agricultural areas, and its thermal insulation effect is better than that of grass. Generally, when sewing quilts, a layer of waterproof material should be used outside to prevent cotton wool from getting wet. Standard quilts are generally made of cotton with a thickness of 2 kg/m2, 3 cm to 4 cm, a width of about 4 m, and a length of 0.5 m longer than the arc of the lighting surface of the front roof for sealing. In some semi-agricultural and semi-pastoral areas, wool is also used to replace cotton wool as a thermal insulation quilt in solar greenhouses. Both cotton wool and absorbent cotton are generally made of non-commercial materials or leftovers from industrial products to reduce costs. In addition to the above-mentioned traditional thermal insulation quilt, there are two kinds of materials that are most widely used at present: one is to use needled felt as the thermal insulation core, and both sides have waterproof protective layers; The second is to use foamed polyethylene materials. The former is cheap, can make full use of industrial waste and realize the recycling of resources, and is an environmentally friendly material. However, due to the different sources of raw materials, the performance of this material is quite different. Especially when sewing thermal insulation quilt, there will be many pinholes on the surface of the product. Some of these pinholes may be waterproof, but most of the products are not waterproof, or even if they are waterproof before leaving the factory, after using for a period of time, the waterproof at the pinholes cannot be well maintained because the thermal insulation is often rolled. Because of the water seepage at the needle hole of the insulation quilt, after it rains or snows, the rain easily enters the insulation core of the insulation quilt, which makes the insulation core damp and reduces its insulation performance. Moreover, because the needle holes for sewing the thermal insulation quilt are small, the water vapor entering the thermal insulation core is difficult to be discharged through the needle holes, and the material for protecting the thermal insulation core is relatively dense waterproof material. Therefore, after long-term use, the insulation quilt will lose its insulation performance due to internal moisture, or it will lose its use function completely due to internal moisture and mildew. In addition, the insulation core of the insulation quilt is fluffy and has good insulation performance when the product leaves the factory. However, after being used for a period of time, the fluffy insulation core will often become dense due to the extrusion and pulling of the curtain roller, or the insulation core with uniform thickness will be drawn into uneven thickness, or even holes will appear, which will lead to the local insulation performance of the insulation quilt decline. Waterproof materials commonly used for this kind of insulation are canvas, Oxford cloth and polyester cloth. Its waterproof performance is obtained by waterproofing the surface of the material. In order to enhance the insulation effect of the insulation quilt, in addition to the necessary insulation core and waterproof layer, some materials such as non-woven fabric, plastic film and kraft paper are added between them, and some aluminum foils are stuck on the inside of the insulation quilt to block indoor long-wave radiation. In a word, there are many kinds of such materials on the market, and the performance and price of products are also very different. Greenhouse producers must identify the performance of core materials when choosing to use such materials, so as not to be deceived. Foamed polyethylene thermal insulation quilt is a kind of light closed-cell self-waterproof material. The internal void formed in the foaming process of materials is the main reason for the formation of thermal insulation performance. Because the still air in a small space has good heat insulation performance. Because the internal gaps of the material are not connected with each other, it is difficult for external moisture to directly enter the material, which overcomes the problem that the moisture-proof performance of the thermal insulation core material is reduced, saves the waterproof layer of the material and realizes the self-waterproofing of the material. This material is light in weight, moisture-proof and labor-saving after foaming, so the power requirements for shutters are correspondingly reduced. However, due to its light weight and poor wind resistance, this material must be equipped with a pressing quilt line to ensure that the insulation quilt will not be lifted when there is wind. In addition, because this material is a by-product of oil, its price is also rising in the case of increasingly tight global oil supply, which has affected the large-scale promotion of this material. In a word, the research and development of new thermal insulation material for front roof mainly focuses on the requirements of easy mechanized operation, low price, light weight, aging resistance and waterproof. In terms of thermal insulation performance, it is generally required to reach or approach the performance of grass.