Method for preparing phenyl benzoate ultraviolet absorber through ester exchange

The invention provides a method for preparing a phenyl benzoate ultraviolet absorber through ester exchange. The method comprises the steps that at least one hindered phenol in the formula I reacts with alkali at 100-140 DEG C to obtain hindered phenol salt, then the hindered phenol salt reacts with at least one benzoate compound of the formula II at 110-195 DEG C, and the absorber is obtained. Accordingly, the disadvantages of being high in production cost, large in industrial waste water and the like caused by the traditional acyl chloride process are avoided; the disadvantages of poor product selectivity caused by an esterification method, low atomic utilization rate caused by an acid anhydride method and the like are avoided; in addition, the method has the advantages of being low in production cost, easy to operate and implement, high in reaction speed, high in single yield of products and capable of recycling and mechanically applying unreacted raw materials, so that the method is more suitable for indu