The invention provides a method for preparing a N,N-dimethyl-1-naphthylamine compound from terminal alkyne, o-bromoacetophenone and a N,N-dimethylamide compound. According to the present invention, the method uses cheap and easily available raw materials and a copper catalyst, and has characteristics of strong functional group compatibility, easy separation of the target product, simple and convenient operation, safety, reliability and high yield of the product; with the method, the problems of low yield, requirement of substrate pre-functionalization, not wide applicability, complex operation, use of ligands, use of precious metals, use of toxic organic solvents, and the like of other synthesis methods are solved; and the method has potential application prospects in fluorescent probes, dyes and bioactive drugs.