NOVELTY - Preparing esomeprazole sodium involves adding omeprazole to the mixed solution of absolute ethyl alcohol and sodium hydroxide, adding disodium hydrogen phosphate, crystallizing to form omeprazole sodium, adding titanate and D-diethyl tartrate, and reacting to form omeprazole sodium complex; adding solvent A, triethylamine and S-mandelic acid, stirring, filtering to form esomeprazole sodium complex; adding inorganic alkali and solvent B, stirring, drying, and evaporating to form crude esomeprazole; adding solvent C and sodium hydroxide to form crude esomeprazole sodium; and purifying.    USE - For preparing esomeprazole sodium (claimed).    ADVANTAGE - The method is simple, environmentally friendly and suitable for industrial scale production; has low cost; and significantly improves yield and purity.    DETAILED DESCRIPTION - Preparing esomeprazole sodium involves adding omeprazole to the mixed solution of absolute ethyl alcohol and sodium hydroxide in stirring reaction for 2-3 hours, adding disodium hydrogen phosphate to stirring for 1.5 hours, the reaction liquid to dryness, using acetone to crystallize to form omeprazole sodium, where the disodium hydrogen phosphate and the omeprazole having a mol ratio of 1:1:2; adding titanate and D-diethyl tartrate, stirring, reacting for 1-2 hours, and evaporating to form omeprazole sodium complex; taking the omeprazole sodium complex in solvent A, adding triethylamine and S-mandelic acid, stirring for 8-10 hours, filtering to form the esomeprazole sodium complex, where the solvent A is selected from ethanol, acetone and/or isopropyl alcohol; adding the esomeprazole sodium complex in inorganic alkali and solvent B, stirring for 2 hours, layering, after extraction with a solvent B alkaline layer was acidified, drying, and evaporating to dryness under reduced pressure to form crude esomeprazole, where the inorganic alkali is selected from sodium hydroxide, potassium hydroxide, sodium bicarbonate or potassium bicarbonate, and the solvent B is selected from ethyl acetate and/or methylene dichloride; adding the esomeprazole in solvent C, adding sodium hydroxide or sodium phosphate, stirring for 3 hours, and evaporating to dryness under reduced pressure to form crude esomeprazole sodium, where the solvent C is selected from methanol, methanol aqueous solution, ethanol or ethanol; and purifying the crude esomeprazole sodium to form esomeprazole sodium.