Close-structure expansion perlite (also called glassy perlite) is a new type thermal insulating material after our nearly 10 years cooperation with domestic research departments. The success of the new type material breaked the technical monopoly by Armerica, Japan and France in Chinese market and upgraded overally the processing level in Chinese perlite industry, in the mean time saved a lot of foreign exchange resource for country. The profuct require special particle size perlite ore, and take expansion in electric furnace. By this way, especially the precisely controlling the temperature and the material’s retaining time in furnace , the surface of expansion perlite shall be melted and close all air cells. The apperance come out ball but cell inside. Compared to traditional open-structure perlite, besides the same thermal insulating and acoustic insulation properties, its outstanding characteristic is for a high intensity, low water absorbability as well as a good miscibility. This material is in a premising prospect to substitute partially for similar ones in lightweight fire-Residtant, glassy particle in explosive making industy.