Preparation method of high-performance low-acid-value phosphate ester

The invention relates to the field of chemical production, and discloses a preparation method of high-performance low-acid-value phosphate ester, wherein the preparation method is characterized by comprising the following steps: mixing phenol, phosphoric acid, a water-carrying agent and a catalyst to obtain a first reactant; heating the first reactant to 80-160 DEG C for esterification reaction, and obtaining a second reactant after the reaction is finished; separating the second reactant to obtain a first organic phase; washing the first organic phase by using an alkaline solution with a first concentration at a first temperature, and separating to obtain a second organic phase after washing is completed; washing the second organic phase with purified water at a second temperature, and separating after washing is completed to obtain a third organic phase; and steaming to remove the organic solution from the third organic phase, and carrying out filter pressing to obtain phosphate ester. According to the meth