The invention relates to a method for preparing aryl trifluoroethoxyl ether. The method includes the steps that aryl boron compounds and trifluoroethanol are added to organic solvent, a copper salt catalyst, a ligand and an oxidizing agent are added, a reaction is conducted in a stirring mode for 1-40 hours at the temperature of 0-60 DEG C, filtering is conducted, column chromatography isolation is conducted, and the aryl trifluoroethoxyl ether is obtained. The method is simple in operation, raw materials are easy to obtain, the reaction condition is mild, the substrate universality is wide, the environmental friendliness is achieved, and the method is applicable to industrial application.