The invention provides a preparation method of azithromycin amine. The preparation method is characterized by adopting a one-pot reaction method. The preparation method comprises the steps of carrying out Beckman rearrangement for erythrocin A9- oxime, water and rearrangement reagent, adjusting the pH value to be 3.0 to 7.0 after the reaction is ended, adding reducing agent to reduce the reactants, and obtaining the azithromycin amine through acid hydrolysis and crystallization. The one-pot reaction of the Beckman rearrangement and reduction is realized by adopting water as the solvent, so that the time for producing erythrocin A9- oxime or erythrocin A9-oxime thiocyanate and the azithromycin amine can be greatly shortened, the procedures can be reduced, the emission of waste gas, waste water and industrial residue can be reduced, the yield is improved by 1 to 3 percent compared with the original process, and the production cost of the azithromycin is further reduced. The midbody erythrocin A6, 9 imino ether is not extracted, and the reaction condition is moderate; the water is used as the reaction solvent, less waste (waste water, waste gas and industrial residue) is produced, and the environmental friendliness can be realized.