The invention relates to a novel green and practical synthesis method of a N,N-dimethyl pyridine compound. The reaction method is characterized in that common inorganic alkaline and water are respectively used as an accelerant and a reaction solvent; under the mild condition and in air, 2-halogenated pyridine derivatives and N,N-dimethylformamide compounds can be smoothly promoted to selectively perform dehalogenation amination reaction to generate corresponding N,N-dimethyl pyridine derivatives. The direct amination reaction of cheap and easy-to-obtain inorganic alkaline promoted 2-halogenated pyridine compounds and N,N-disubstituted methylformamide compounds is innovatively realized for the first time; the limitation that a metallic catalyst needs to be used by a traditional method is overcome; a bran-new strategy is provided for laboratory preparation and industrial production of the N,N-dimethyl pyridine compound.