The invention relates to a method for preparing a bicyclo-aromatic chemical through 2-methylfuran, formaldehyde and methyl alcohol. The method includes the steps that the 2-methylfuran and the formaldehyde are subjected to a hydroxyalkylation reaction under the effect of an acid catalyst at the temperature of 50 DEG C to 150 DEG C, and an intermediate product di(5-methylfuran)methane is generated;the intermediate product di(5-methylfuran)methane and the methyl alcohol are subjected to a cycloaddition reaction and a dehydration reaction together at the temperature of 350 DEG C to 600 DEG C, and di(4-methylphenyl)methane is generated; the reaction raw materials are directly injected into a reaction tube or are blown and swept to a fixed bed reactor through inert gas, and the bicyclo-aromatic chemical is obtained through a catalyst bed layer; the catalyst is cheap solid acid, a reaction substance is the 2-methylfuran, and the formaldehyde and the methyl alcohol can be obtained through biomass resources. The reaction working procedure in the process reaction is simple, the selectivity of the target product is high, and a new path for preparing a bicyclo-aromatic compound through the biomass resources is provided.