A three-component mineral material consisting of mica, clay and carbonate was used to make a composite characterized by heat insulation, insulation, anti-static pressure. Its chemical composition, mineral phase, electric property, mechanical property and temperature in use were analysed. The ordinary procedure has been established for composing the mica composite and the thin board. The test under high temperature and medium pressure shows that the mica composite has good properties of heat insulation, insulation, and anti-static pressure. It can replace the asbestos board in the process of firing the man-made diamond products.