Abstract: Principle and development of main ammonium chloride conversion methods,such as sulfuric acid method,acid sulfate method,metal oxide compound method,and catalytic decomposition method,were reviewed.Advantages and disadvantages of different methods in industrial production were discussed.Sulfuric acid method has failed to make full use of ammonia resources,and obtained sulphate cannot be recycled and production cost is high.Acid sulfate reaction temperature is so high that it will cause raw material ammonium chloride to vaporize,and problem of separation ammonium chloride from hydrogen chloride gas cannot be solved in project.Metal oxide compound method has mild reaction conditions and higher yield of ammonia and hydrogen chloride.It is the main method for research of ammonium chloride coversion in China.But the craft route is long,the equipment investment is large.Due to expensive replacement agent and harsh reaction conditions,catalytic decomposition method is not benefit to industrialization.