A preparation method of a large-pore aluminum 
oxide with double-pore spread structure. First, aluminum 
oxide, a poreforming agent and 
solid silica are mixed, and receive ball-milling treatment in a ball milling 
machine; the mixture 
after treatment is kneaded into a plastic body by 
aqueous solution with cationic surfactant, 
extrusion aid, peptizator, etc. dissolved in, and put into the 
water vapor atmosphere to be treated; and the prepared mould is dried and baked, to obtain the final aluminum 
oxide carrier. The poreforming agent is one or the mixture of 
carbon black, 
cellulose and 
starch, and the loading is 3.0 to 15w percent of the weight of the aluminum oxide; the 
solid silica is silica 
aerogel, and the loading is 1.0 to 10w percent of the weight of the aluminum oxide; in the ball milling 
machine, the ball-material ratio is 15:1 to 10:1, and the ball milling time is 0.5 to 3.0h; the treatment temperature of the 
water vapor is 120 DEG C to 180 DEG C, and the 
treatment time is 0.5 to 6.0h. The aluminum oxide prepared by the invention has double-peak channel structure and high strength, and is applicable in fields of 
petrochemical, 
petroleum processing, 
environmental protection, etc.