The corundum-spinel castable was prepared by using tabular alumina, white fused alumina,sintered magnesia-alumina spinel,active α-Al2O3 micropowder and calcium aluminate cement as main raw materials.The effects of different firing temperature on the physical properties and microstructure of corundum-spinel castable were studied.The results show that part of CA6 crystals begin to form after firing at 1 400  ℃.With the increase of firing temperature,a large number of CA6 crystals form and grow up,interspersing in the pores to form a continuous network structure.The continuous network structure makes the sample become dense and strengthens the combination of the matrix,and makes the fracture mode of the sample gradually change from intergranular fracture to transgranular fracture,so that CMOR ,HMOR and the thermal shock stability of the sample become continuously improved.After firing at 1 550  ℃,the HMOR of the sample is the highest and the thermal shock stability is the best.After firing at 1 400  ℃ to 1 450  ℃,the formation of CA6 crystal is dominant,and the sample shows expansion after firing; after firing at 1 500  ℃ to 1 550  ℃,the sintering is dominant,and the sample shows shrinkage after firing.After firing at 1 550  ℃,the shrinkage of the sample reached 0.25%.