A method for synthesizing an O-hydroxy phenyl ether relates to a method for applying a novel catalyst to prepare the O-hydroxy phenyl ether, which is synthesized through a gas-phase alkylation betweenthe cathecol and the ethanol. The composition expirical formula of the active center of the catalysts is Al< 1 >P< a >X< b >; wherein, X is Cr, Mg, V or Zr, a is more than or equal to 0.9 and less than or equal to 1.5 and b is more than 0 and is less than or equal to 0.3; the aluminum nitrate is used as the aluminum source, the phosphoric acid, the ammonium dihydrogen phosphate and the ammonium phosphate or the ammonium phosphate are used as the phosphorous source and the nitrate, the zirconium oxychlorid and the ammonium metavanadate of Mg and Cr are used as the raw materials of X; the reaction between the catechol and the ethanol is carried out in a fixed bed reactor and the molar ratio of the ethanol to the catechol ranges from 2 to 7:1; the ratio of the mole number of the catechol tothat of the catalysts every hour ranges from 0.05 to 0.75 as Al, the reaction space velocity ranges from 0.1 to 1.5h<-1> as the volume of the liquid and the reaction temperature ranges from 533K to 593K. The catalysts adopted by the invention have simple compositions, the raw materials are simple and easy to be obtained and the specific surface area is larger; the invention delivers high yield andhigh stability for the target reaction.