The invention discloses a trimetazidine hydrochloride intermediate preparation method. The method takes 1,2,3-trichlorobenzene (II) as a starting raw material; a nucleophilic substitution reaction is performed under catalysis of a catalyst in a methanol solution of sodium methylate for obtaining an intermediate (III); and then a Duff reaction is performed on the intermediate (III), and finally an intermediate (I) is obtained. The solvent used in the method provided by the invention has low toxicity, and can be recycled and reused, so that the three-waste (waste gas, waste water and industrial residue) emission is reduced. The method simplifies the operation steps, reduces the production cost and is more beneficial to industrial reactions. The post-treatment process of the method is simpler, so that on the basis of increasing impurity removing efficiency, the complexity of the technological process is reduced further.