The invention relates to a method for preparing 2-trifluoromethylbenzo oxazole, including the steps of as follows: under the protection of nitrogen gas, using carbon tetrachloride as solvent, adding triphenyl phosphine and triethylamine in the reacting container, blending and lowering the temperature to 0 deg.C under the ice water bathing; then adding in trifluoro acetic acid, blending 10-20 minutes, finally adding in carbon tetrachloride dissolved ortho-aminophenol, where the molar ratio of four reactants triphenyl phosphine, triethylamine, trifluoro acetic acid, and ortho-aminophenol is (3-3.5) : (3-3.5) : 1 : (1-1.2); heating to start acute reaction, immediately removing heat source, continuing returning and reacting 3-5 hours, as the reaction ends, vacuum evaporating the solvent from the reacting solution, then adding the solvent petroleum mixed of petroleum ether and acetate in the bulk ratio of 10 to 1 into a bottle to mix into a, soaking, pump filtering, washing the solid in buchner funnel with the mixed solution; making chromatographic resolution on the obtained liquor, and collecting the 25-28 deg.C/2mmHg fractions, thus obtaining the products 2-trifluoromethylbenzo oxazole. The material materials of the invention are easy to obtain, the operation is extremely simple, and the synthesis is one-boiler made. The method has high yield, suitable to large-scale production.