a method of preparing - 2 - amino - 5 - methoxytetralin hydrochloride - 2 - amino - 5 - methoxyl - 1 , 2 , 3 , 4 - tetrahydronaphthalene hydrochloride ], comprising the steps of : producing a compound by addition - elimination reaction of 5 - methoxy - 2 - tetralone and r -- a - phenylethylamine ; producing a compound by reduction reaction of the compound with a reducing agent ; and producing a compound hydrochloride by reacting the compound with a salt - forming agent , then carrying out reduction reaction with a palladium - carbon catalyst to produce - 2 - amino - 5 - methoxytetralin hydrochloride . the method can significantly increase the yield of - 2 - amino - 5 - methoxytetralin hydrochloride with short synthetic path , low preparation cost and less pollution , which is environmentally friendly and is suitable for medical industrialized production . the structural formulae of the compound and the compound are : resepectively .