The invention discloses a method for preparing a dibenzol derivative. The synthesis path of the dibenzol derivative is shown in the description, wherein Ar1 and Ar2 are each selected from phenyl, methyl substituted phenyl, ethyl substituted phenyl, methoxyl substituted phenyl and halogen substituted phenyl. The synthesis process comprises the steps of adding a compound 1, copper chloride dehydrate and lithium bromide into a reaction bottle, adding a reaction solvent for constant-temperature reaction at 30 DEG C in the atmosphere of oxygen under a blue light source, conducting TLC tracking monitoring, and conducting column chromatography isolation after reaction ends to obtain a compound 2. By the adoption of the method, the dibenzol derivative can be prepared in an environment-friendly mode. The method has the advantages that reaction conditions are mild and environment-friendly, cost is low, efficiency is high, reaction path is short, and atom economy is high.