Method of preparing phosphate

The invention provides a method of preparing a phosphate. The method comprises the following step: enabling a pyrophosphate active compound expressed by formula II to react with uridine monophosphate expressed by a formula III or a salt thereof in a hydrophilic solvent under the action of a bimetallic ion composite catalyst to obtain P1,P4-bis (5'-uridine group) tetraphosphate expressed by formula I. In the formula II, X is imidazolyl, N-methyl imidazolyl, or 1, 2, 4-triazolyl; and the bimetallic ions in the bimetallic ion composite catalyst are a combination of any two of Zn2+, Mn2+, Mg2+, Fe2+, Fe3+ and Al3+. The method of preparing a phosphate employs a bimetallic catalytic system and can achieve high-efficiency and easy separation preparation of diquafosol.