With 4 methyl 4′ nitrodibenzene ether,thiourea dioxide and sodium hydroxide as starting materials,the 4 methyl 4′ aminodibenzene ether is synthesized in aqueous ethanolic solution.The optimum conditions of the reaction are as follows∶4 melthyl 4′ nitrodibenzene ether∶thiourea dioxide∶sodium hydroxide is 1.0mol∶3.9mol∶7.5mol,the duration of additron of thiourea dioxide for the present scale is 1.0h,suitable temperature is 50℃,reaction time is 40min.The yield of 4 methyl 4′ aminodibenzene ether reaches 93.1%.