The invention relates to a synthetic method for a diaryl ketone compound which can be used as a drug intermediate and is shown as a formula (III) which is described in the specification. The method comprises a step of reacting a compound (I) as described in the specification with a compound (II) as described in the specification in a nitrogen atmosphere and organic solvent in the presence of a catalyst, an oxidizing agent, alkali and a promoter so as to obtain the compound as shown in the formula (III). In the formula (III), R1, R2 and R3 are independently selected from a group consisting of H, C1-6 alkyl groups, C1-6 alkyloxy groups, halogen and nitro groups; and X is halogen. According to the method, through selection of an appropriate substrate and usage of a reaction system composed of the catalyst, the oxidizing agent, the alkali and the promoter, high yield of the target product, i.e., the diaryl ketone compound, is realized; and a brand novel synthetic method is provided for the compound, and the synthetic method has wide market application prospects.