The invention belongs to the technical field of preparation of fluoroalkyl-substituted aromatic hydrocarbons, and in particular relates to a preparation method of a trifluoroethyl-substituted aromatic compound. The method takes a trifluoroethyl source reagent (I) and arylboronic acid Ar-B (OH) 2 (II) as raw materials, adopts a cheap and easily available nickel catalyst and pyridine ligands as a catalytic system, and efficiently introduces trifluoroethyl to an aromatic ring group, so that the trifluoroethyl-substituted aromatic compound can be obtained. According to the method, mild reaction conditions, high operability and low raw material cost are achieved, reaction scale is easy to expand, and product separation is simple, so the method has the advantages of being suitable for industrial production.