NOVELTY - Preparing high purity esomeprazole sodium comprises stirring omeprazole sodium salt with alcohol, adding water, stirring until the solution is clear, subsequently adding D-(-)-diethyl tartrate, titanium tetraisopropoxide, triethylamine and L-(+)-mandelic acid, reacting, filtering to obtain white solid inclusion complex, dissolving in ethyl acetate, washing ethyl acetate layer with e.g. aqueous ammonia, extracting with methylene dichloride, concentrating, dissolving in ethyl acetate, adding an adsorbent, filtering, concentrating filtrate, mixing with e.g. sodium hydroxide and crystallizing.    USE - The method is useful for preparing high purity esomeprazole sodium (claimed).    ADVANTAGE - The method utilizes titanium complex, which is easy to mix with the suspension and is difficulty to split; solves the problem of cationic ammonia in formation of inclusion complexes; is suitable for industrial production and economical; provides high purity and high yield product; and does not generate harmful gas.    DETAILED DESCRIPTION - Preparing high purity esomeprazole sodium comprises (a) adding omeprazole sodium salt into organic alcohol in a volume ratio of 1:5-25, stirring and adding water, where the weight ratio of omeprazole sodium and water is 0.02-0.2, stirring at room temperature until the solution is clear, (b) adding D-(-)-diethyl tartrate into the solution in a mol ratio of 1:0.8-1.2, adding titanium tetraisopropoxide, where the mol ratio of D-(-)-diethyl tartrate and titanium tetraisopropoxide is 1:0.4-1.1, adding triethylamine after 5-30 minutes in a volume ratio of 1:0.6-2, adding L-(+)-mandelic acid in a molar ratio of 1:0.8-2, refluxing and reacting at 40 degrees C for 2-4 hours, and filtering to obtain white solid inclusion complex, (c) dissolving the inclusion complex in ethyl acetate, where the volume ratio of omeprazole sodium salt and ethyl acetate is 1:1-20, washing with inorganic acid salt solution, washing ethyl acetate layer with aqueous ammonia at -5 to 30 degrees C, washing with glacial acetic acid to weakly acidic pH, extracting with methylene dichloride, concentrating to dryness to obtain esomeprazole free base crude product, (d) dissolving esomeprazole free base product in ethyl acetate, where the volume ratio of omeprazole sodium salt and ethyl acetate is 1:0.5, (d) adding an adsorbent, where the weight ratio of omeprazole sodium salt and adsorbent is 1:0.05-1, stirring and filtering, concentrating the filtrate to dryness to obtain esomeprazole free base pure product, and (e) mixing esomeprazole free base pure product with sodium hydroxide and organic solvent solution of salt and crystallizing with isopropyl ether.