Non woven fabric, also known as harvest fabric. Long fiber non-woven fabric is a new covering material with good breathability, moisture absorption, and certain light transmittance. Non woven fabrics are divided into thin, thick, and thickened types, usually expressed in grams per square meter, such as 20 grams per square meter, 30 grams per square meter, 40 grams per square meter, and so on. The thickness of non-woven fabrics varies, resulting in differences in water permeability, shading rate, and ventilation, as well as different coverage methods and uses. Generally, thin non-woven fabrics of 20-30 grams per square meter have high water permeability and ventilation, and are lightweight. They can be used for floating surface coverage in outdoor and greenhouses, as well as for insulation curtains in outdoor small arches, greenhouses, and greenhouses. They provide insulation at night and can increase the temperature by 0.7-3.0 ℃. The non-woven fabric used for greenhouses of 40-50 grams per square meter has low water permeability, high shading rate, and heavy weight. It is generally used as an insulation curtain for greenhouses and inside greenhouses, or can replace grass curtains to cover the outside of small greenhouses to enhance insulation. This type of non-woven fabric for greenhouses is also suitable for shading, seedling cultivation, and cultivation in summer and autumn. Thickened non-woven fabric (100-300g/m2) replaces straw curtain and straw mulch, and carries out multi-layer coverage in greenhouses and greenhouses together with agricultural film. According to research, non-woven fabrics used for covering greenhouses have a significant thermal insulation effect compared to grass curtains, and are lighter in weight and easier to manage. It is expected to achieve mechanized or semi mechanized uncovering. Non woven fabrics have long been widely used in developed countries such as Japan, the United States, the Netherlands, and Canada. The introduction of non-woven fabric technology in China has not been long. Currently, there are few types and specifications of products, high prices, and a certain gap in quality compared to similar foreign products. At the same time, there is not enough research and promotion work on coverage technology, so the promotion area is still not large. But with the improvement of non-woven fabric production technology and further improvement of covering technology, non-woven fabrics will be widely used in the development of vegetable off-season cultivation.