The invention relates to the field of preparation of refractory materials, particularly a method for preparing high-quality calcium magnesia by superhigh-temperature calcination, which is characterized by comprising the following steps: preparing dolomite and magnesite into a raw material in which the CaO content is 15-20 wt% and the MgO content is 80-85%; adding the raw material into a ball milling tank, grinding and mixing, and meanwhile, adding water to carry out slaking and slurrying; and drying the slurry, adding calcium lignosulphonate, evenly mixing, pressing into green bricks, and calcining. The calcination process comprises the following steps: heating to 1100 DEG C, keeping the temperature for 3-5 hours, heating to the final calcination temperature of 2000-2200 DEG C, keeping the temperature for 5-7 hours, vacuumizing, cooling with water to 1000 DEG C, introducing protective hydrogen, and continuing cooling with water to room temperature. Compared with the prior art, the calcium magnesia has the advantages of high hydration resistance and high corrosion resistance, thereby basically solving the problem of high hydration tendency in the magnesium-calcium refractory material, and facilitating the storage, transportation, building and the like in future.