The invention discloses thermal-shock-resistant corundum-spinel refractory castable which comprises the following raw materials in percentage by weight: 65-80% of corundum particles and fine powder, 3-10% of aluminum oxide fine powder, 2-8% of materials containing Zr, 10-15% of magnesium-aluminum spinel fine powder, 3-8% of bonding agent, 0.05-0.1% of organic fiber (additional) and 0.2-0.6% of water reducing agent (additional). The preparation method of the corundum-spinel refractory castable comprises the following process steps of burdening, mixing, molding, maintaining, drying, storage and transportation, using and the like. Compared with the prior art, the thermal-shock-resistant corundum-spinel refractory castable provided by the invention has high thermal-shock-resistant property, and favorable high-temperature resistance and anti-erosion capability, and is suitable for steel ladles, intermediate ladles, RH (relative humidity) immersion tubes, cement high-temperature kilns and the like.