Method for catalytically synthesizing triethyl phosphate by phase transfer

The invention relates to a method for catalytically synthesizing triethyl phosphate by phase transfer. Diethyl phosphate sodium salt is used as a raw material, phase transfer catalyst is added into the material, and ethylation reagent is added in an organic solvent and water system to generate triethyl phosphate; and the triethyl phosphate is separated and purified to obtain a finished product. Compared with the prior art, the catalyst has lower cost, the organic solvent and water are adopted as mixed solvent, the organic solvent can be recycled, so the method is friendly to environment, reduces the synthesizing cost, not only recycles the diethyl phosphate sodium salt, changes waste into valuable organic phosphor resources, reduces environmental pollution, but also provides a novel way for industrial production of the triethyl phosphate. The method not only has the advantages of few reacting steps, convenient operation, high yield, high product purity and easy industrial production, but also reduces environmental pollution of side product phosphoric acid, diethyl ester and sodium salt in a fluorescent whitening agent production process.