Preparation method of dapoxetine hydrochloride

The invention discloses a preparation method of dapoxetine hydrochloride. The preparation method comprises that 3-chloropropiophenone and naphthol as initial raw materials and (S)-tert-butanesulfinyl amide undergo a condensation reaction in a solvent, the intermediate is reduced through a reducer BH3 and then is further subjected to deprotection, the reaction product undergoes a methylation reaction and the reaction product undergoes a salification reaction to produce dapoxetine hydrochloride. The preparation method has mild conditions, can be operated simply, realizes a low cost, is free of resolution or use of an expensive heavy metal catalyst, has a simple aftertreatment process, has a high product yield, produces the product with high chemical purity and optical purity and is suitable for industrial production.