Preparation method of esomeprazole sodium

The invention provides a preparation method of esomeprazole sodium. The method provided by the invention is simple to operate, is high in yield and purity of the esomeprazole sodium and is suitable for industrial production. A specific reactive solvent is screened, the addition amount of water is regulated, and the specific reaction temperature, time and pH value are controlled, so that the esomeprazole sodium of which the purity exceeds 99% and the yield exceeds 32% is obtained.