The products properties and technical data of conventional refractory bricks and refractory bricks with low thermal conductivity were analyzed and compared. The application of nano thermal insulation materials in precalcing system was introduced. The practice shows that the low thermal conductivity refractory bricks has low thermal conductivity, high strength and light weight, which significantly reduces the heat loss of the firing system, reduces the operation load of the rotary kiln and saves the energy consumption. The thermal insulation performance of nano thermal insulation material is obviously better than that of ordinary calcium silicate plate.