Preparation method of modified alumina

The embodiment of the invention discloses a preparation method of modified alumina, and relates to the technical field of inorganic catalytic materials. The preparation method includes the following steps that 1, a rare earth modifier solution containing a dispersant and a sodium aluminate solution containing a pore expanding agent are configured for use; 2, Me(OH)x slurry is prepared through a co-precipitation method; 3, the prepared Me(OH)x slurry is aged at 50-90 DEG C for 24-240 hours to obtain a wet Me(OH)x filter cake; 4, the wet Me(OH)x filter cake and an alkali aqueous solution are subjected to a hydrothermal reaction in a pressure kettle to obtain dry Me(OH)x powder; 5, the dry Me(OH)x powder is calcined to obtain the modified alumina. The preparation method has the advantages that the technological process is short and simple, the construction cost is low, the production cost is low, and the physical and chemical properties of the product are excellent, the high-temperature thermal stability of an a