The invention discloses a high-strength corundum ceramics and a preparation method thereof. A ceramic blank comprises the following components: 18-22 parts of aluminum oxide, 12-15 parts of quartz, 0.5-1.0 part of talc, 27-30 parts of feldspar, 25-29 parts of kaolin, 10-14 parts of chinastone and 0.5-1.5 parts of blank body plasticizing agent. In sintered porcelain, the aluminum oxide content is higher than 30 percent. The method comprises the following steps: ball-milling and pulverizing a blank; adding water and mixing to obtain blank slurry; deironing and press-filtering the blank slurry into a mud cake and roughly smelting the mud cake; mildewing the roughly smelted mud cake and refining the mildewed mud cake; rolling and moulding the refined mud in a die to obtain a blank body; drying, washing and glazing the blank body and sintering at 1,280-1,320 DEG C for 15-18 hours to obtain a finished product. The product has favorable mechanical strength, and the impact resistant capability of the product is more than four times that of common ceramics; and the product has favorable thermostability, no crack after thermal shock at 200 DEG C/20 DEG C three times, the water absorption rate of lower than 0.1 percent, is more dense, firm and durable and is particularly suitable for an oven, a microwave oven and a dish-washing machine.