The invention relates to corundum and spinel castable and a preparation method thereof. According to the scheme, the method comprises the following steps of: blending 1 to 10 weight percent of magnesia-alumina spinel fine powder, 5 to 10 weight percent of white fused corundum fine powder, 5 to 10 weight percent of alpha-Al2O3 micro powder, 2 to 8 weight percent of pure calcium aluminate cement, 0.06 to 0.2 weight percent of poly carboxylic acid water reducing agent, and 0.01 to 0.1 weight percent of organic fiber, and precasting mixed powder; performing dry-blending on 6 to 18 weight percent of partially stable zirconia particles or calcium zirconate particles, 45 to 70 weight percent of tabular corundum particles and 1 to 10 weight percent of magnesia-alumina spinel particles which are used as aggregate for 4 to 6 minutes, adding the mixed powder, and milling for 15 to 30 minutes; and adding water in an amount which is 3 to 6 percent based on the weight of the mixed powder and aggregate, milling for 3 to 5 minutes, vibrating and performing casting moulding, curing for 20 to 26 hours, demoulding, drying at the temperature of between 100 and 120 DEG C for 20 to 26 hours, raising temperature to 1,450 to 1,750 DEG C, and preserving heat for 2 to 4 hours. The prepared corundum and spinel castable is high in thermal shock resistance, high-temperature strength, and strength retention rate after thermal shock, and long in service life.