The invention provides a method for preparing high-performance sintered heat insulating bricks, which comprises the following steps: step 1, sludge from urban domestic sewage treatment plants or paper mill sludge is concentrated, filtered and dried; step 2, clay, sludge Carry out natural drying, crushing, crushing and sieving; step 3, mix the raw materials evenly to obtain the dry mixture, add water and stir evenly; step 4, carry out aging treatment on the wet mixture, and the aging time should exceed 24h; step 5 1. The brick blanks are molded to obtain bricks; step 6, the bricks are dried naturally at room temperature and then sent to the tunnel drying kiln for drying; step 7, after drying, the bricks are directly sent to the tunnel sintering kiln, the sintering temperature is 950 ~ 1100 ℃, The holding time of the brick body at the highest sintering temperature is 1 to 3 hours. The invention overcomes the disadvantages of poor mechanical properties and high thermal conductivity of traditional thermal insulation bricks, and realizes the production of high-performance thermal insulation bricks with a large amount of sludge; the source of raw materials is wide, the cost is low, and various production and domestic sludges are consumed in large quantities.