The energy consumption of industrial kilns accounts for 30%of total energy consumption and 60%of industrial energy consumption in China.However,the thermal efficiency of the kiln is as low as about 30%.It is urgent to find solutions to improve the thermal efficiency.In this study,using high emissivity powders silicon carbide,copper oxide as fillers,and sodium silicate as binder,a high emissivity coating was prepared on the mullite light cotton brick matrix by brush coating method,and its energy saving assessment was tested.The results show that the emissivity of CuO coating is stable above 0.87,and that of SiC coating is stable above 0.89.Besides,the coating prepared on the surface of mullite fiber cotton brick can shorten the heating time and decrease energy consumption.The silicon carbide-sodium silicate coating can shorten the heating time by 4.2%,and save energy by 5.7%after holding for 5 hours.The copper oxide-sodium silicate coating can shorten the heating time by 2.9%,and save energy by 6.4%after holding for 5 hours.This research provides a new coating method for energy saving of kiln,and has a good application prospect.