NOVELTY - Preparing febuxostat intermediate (II) comprises dissolving ethyl 2-(4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (III) and paraformaldehyde into aprotic organic solvent A, performing hydroformylation reaction to obtain ethyl 2-(3-formyl-4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (IV); reacting compound (IV) with hydroxylamine hydrochloride, aldoxime dehydrating to obtain ethyl 2-(3-cyano-4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (V); dissolving compound (V) in aprotic organic solvent B, and performing Mitsunobu etherification to obtain compound (II).    USE - Method for preparing febuxostat intermediate.    ADVANTAGE - The method avoids introduction of high b.pt. solvent and poisonous catalyst; has simple post-treatment, low cost, and little energy consumption; and is environment-friendly, high in yield, non-toxic and suitable for industrial production.    DETAILED DESCRIPTION - Preparing febuxostat intermediate (II) comprises:    (A) preparation of ethyl 2-(3-formyl-4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (IV) by dissolving ethyl 2-(4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (III) and paraformaldehyde into aprotic organic solvent A, performing hydroformylation reaction at 50-90 degrees C for 5-12 hours in the presence of boron trifluoride catalyst to obtain compound (IV), cooling to room temperature, adding proper water, adjusting pH with 20% sodium hydroxide (NaOH) solution to 5-6, separating out product, filtering, drying to obtain yellow solid, where the aprotic organic solvent A is acetonitrile (3%) or tetrahydrofuran, mass ratio of the compound (III) and the paraformaldehyde is 1: 0. 5-1. 2, the acetonitrile is 10 times (V/M, ml/g) of the compound (III), and the mol ratio of compound (III) and ether is 1: 0. 1-0. 5;    (B) preparation of obtain ethyl 2-(3-cyano-4-hydroxyphenyl)-4-methyl thiazole-5-carboxylate (V) by reacting compound (IV) with hydroxylamine hydrochloride at 80-120 degrees C for 3-5 hours in the presence of formic acid and sodium formate, aldoxime dehydrating to obtain compound (V), cooling to room temperature, pouring in an amount of ice water, stirring , filtering, washing filter cake with purified water, then vacuum drying at 50 degrees C over night to obtain dry product, where mol ratio of the compound (IV) and hydroxylamine hydrochloride is 1: 3-6, ratio of compound (IV) and the formic acid is 1: 10-18, and ratio of compound (IV) and sodium formate is 1: 2-5; and    (C) preparation of compound (II) by dissolving compound (V) in aprotic organic solvent B, and performing Mitsunobu etherification reaction at normal temperature for 3-8 hours under the action of catalyst to obtain compound (II), after the reaction, adding water, and then adding 50 times (V/M, ml/g) ethyl acetate to extract, collecting organic phase by anhydrous magnesium sulfate, filtering, evaporating filtrate, washing residue with anhydrous ethanol, and re-crystallizing to obtain yellow solid, where the aprotic organic solvent B is halogenated hydrocarbon, ether or cyclic ethers, ketone or nitrile below four carbon atoms selected from one, the catalyst is triphenyl phosphine or tributyl phosphine and diethyl azodicarboxylate (DEAD), diisopropyl azodiformate (DIAD) mixture, ratio of compound (V) and alcohol is 1: 1. 2-4, the cyclic ether is tetrahydrofuran and is 3-10 times (V/M) of the compound (V), and the catalyst is the mixture of triphenyl phosphine, DEAD and triphenyl phosphine at a mol ratio of 1. 1-1.5: 1. 1-1.5: 1.