The invention discloses a preparation method of an alumina corundum hollow sphere. High alumina bauxite serves as raw material and desilicication material is introduced, which are smelted and purified in a three-phase AC electric arc ore furnace or a DC electric arc ore furnace, sprayed by compressed air and then are sieved to obtain the corundum hollow sphere of 0.2 to 5mm. The alumina with low cost is used as the raw material and the purification of the alumina is realized in the smelting process by adding the desilicication material. The alumina is sprayed and fused to prepare the corundumhollow sphere. The manufacture cost of the corundum hollow sphere can be reduced greatly and the use temperature of the prepared corundum hollow sphere is similar to the use temperature of an aluminahollow sphere. The compression strength is high. Compared with alumina heat insulating material produced through a burnout object addition method, a foam method and an air genetic method, the invention has higher mechanical strength and use temperature and is applicable to being the aggregate of light castables. The damage rate in the construction process is low.