Abstract: The method of design, measuring,preparation and cooling technigues,which were used for the high power CO2 reflector,have been discussed.The influence of the different substrate materials on the reflector has been compared.The result of applications demonstrated that the reflectance of the reflector is higher,the hardness of the coating film is larger and the heat deformation is smaller than those of the rdflectors which adopt copper as substrates and are coated by gold film. In addition,the dirty of this kind reflector can be cleaned by the organic solvent.