NOVELTY - An albendazole preparation method involves adding potassium bromide, ammonium metavanadate and (1H-Benzoimidazol-2-yl)-carbamic acid methyl ester compound (I) into chloroform to obtain a mixture. The mixture is reacted with hydrogen peroxide to obtain (5-Bromo-1H-benzoimidazol-2-yl)-carbamic acid methyl ester compound (II) that is added with absolute potassium carbonate, n-propenethiol and dimethylformamide to obtain carbamic acid methyl ester compound (III). Ester compound (III) is added to concentrated hydrochloric acid, methanol and active carbon to obtain albendazole.    USE - Method for preparing albendazole.    ADVANTAGE - The method enables preparing albendazole with high yield in a simple, cost-effective and environmental-friendly manner with wide application range.    DETAILED DESCRIPTION - An albendazole preparation method involves adding potassium bromide, ammonium metavanadate and (1H-Benzoimidazol-2-yl)-carbamic acid methyl ester compound of formula (I) into chloroform to obtain a mixture. 30% hydrogen peroxide is slowly dropped to the mixture, heated to 75 degrees C for 30-40 minutes and reacted to obtain a reaction solution. The reaction solution is cooled to the room temperature and subjected to layering to obtain water layer and organic layers. The water layer is extracted using the chloroform. The organic layers are combined, washed with the saturated edible salt water solution, dried with the absolute sodium sulfate, filtered and concentrated the filtering liquid to obtain (5-Bromo-1H-benzoimidazol-2-yl)-carbamic acid methyl ester compound of formula (II). (5-Bromo-1H-benzoimidazol-2-yl)-carbamic acid methyl ester compound of formula (II), absolute potassium carbonate and n-propenethiol are added into dimethylformamide to carry out backflow reaction, concentrated to remove partial solvent, poured into the icy water, stirred, crystallized, filtered and washed to obtain crude product of carbamic acid methyl ester compound of formula (III). The carbamic acid methyl ester compound of formula (III) is added into water. Concentrated hydrochloric acid is added to carbamic acid methyl ester compound of formula (III) to obtain crude product solution. Methanol and active carbon are added to the crude product solution, stirred at 60 degrees C for 30-40 minutes, filtered to remove the active carbon, subjected to layering to obtain water layer. 20% of sodium hydroxide aqueous solution is added into the water layer to adjust the PH to 7-8. The water layer is filtered, washed the filtering cake with the icy water and dried to obtain the pure product of the albendazole.