Disclosed is a method for synthesizing benzyl ether from polyhydric phenol, which is characterized in that the method comprises reacting, in the presence of a base and a catalyst, the polyhydric phenol with a benzylating reagent in an organic solvent to which water is added, thereby obtaining a fully-benzylated benzyl ether. The disclosed method is simple, has low production costs and a high product yield; in addition, the use of solvents and environmental pollution are reduced; therefore, the method is easy to implement in industrial scale-up.