The main purpose for setting refractory of the fluidized bed boiler to prevent high temperature oxidation corrosion and wear of boiler high temperature flue gas and material on the metal components. The circulation wear of the materials with heat insulation firstly occurs on the refractory material, which ensures the service life of metal structure, this is one of the important measures to ensure  long-term and safe operation of the circulating fluidized bed boiler, and is one the main characteristics of circulating fluidized bed boiler. The application of refractory is of great significance to reduce the use of metal structure, lower cost, facilitate the maintenance and repairing.