Abstract: A new type of thermal insulation material has been developed. It can be used to cover sun-light greenhouse at night instead of straw-curtain. This is a kind of compound material. Its heat insulation and preservation effect is better than straw-curtain's. It has characteristics of light weight,waterproof,toughness, saving effort, and so on. The price is appropriate. The material does not damage and dirty plastic film because of its smoothness. It was given high evaluation through application of two years in many regions.