The invention discloses a method for synthesizing imine through cross-coupling of hydroxylation phenanthroline copper complex/O2 catalytic oxidation alcohol and amine. According to the method, an economical and cheap hydroxylation phenanthroline copper complex is selected as a catalyst, green O2 is selected as an oxidizing agent, cross-coupling of alcohol and amine is realized under the condition of normal temperature, alkali and an expensive free radical of nitroxide is prevented from being used, and a series of imine compounds are successfully prepared. The method provided by the invention is high in reaction selectivity and relatively wide in a substrate application range, and has a great industrial application potential.