In recent years, Chinese ceramic industry has developed rapidly, producing about 10 million tons of ceramic polishing slag every year, but only 5% is used. The ceramic polishing slag was used as the research object, supplemented by raw materials such as clay, porcelain sand and medium temperature sand, and SiC was used as the pore structure regulator to prepare lightweight ceramic bricks. A series of orthogonal experiments were used to obtain the best sintering system, and explore the effects of firing temperature and milling time on performance of polishing slag lightweight ceramic bricks. The results show that an increase in firing temperature can improve the uniformity of internal connected pores and pores in lightweight ceramic bricks. At 1 160 ℃, volume density, compressive strength, and apparent porosity of lightweight ceramic bricks are the highest, and volume density is 1.24 g/cm3, compressive strength is 35 MPa and water absorption rate is 20.38%, respectively. When the ball milling time is extended from 10 to 110 min, the particles become finer, the surface energy increases, the liquid content increases, and the foaming content increases, resulting in improved uniformity of connected pores and pores.