The present invention discloses a preparation method of N,N-dimethyl-3-hydroxy-3-arylpropylamine. Said method includes the following steps: adding phenyl methyl ketone or 2-acetyl thiophenol and N,N-dimethylformamide dimethyl acetal into solvent including benzene and N,N-dimethylformamide, after the reaction is completed, evaporating solvent, cooling to obtain yellow crystal product, using solvent of ethyl acetate, etc, to make recrystallization and obtain N,N-dimethyl-3-oxo-3-aryl propyleneamine; adopting lithium aluminium hydride as reducing agent, adding N,N-dimethyl-3-oxo-3-aryl propyleneamine and reducing agent into the solvents of benzene, etc., making reaction to obtain product; or adopting sodium borohydride as reducing agent, adding N,N-dimethyl-3-oxo-3-aryl propyleneamine and reducing agent into solvents of acetic acid, etc., making reaction to obtain product; making said product undergo the process of phase separation, evaporating the organic phase obtained by means of phase separation so as to obtain N,N-dimethyl-3-hydrox-3-arylpropylamine.