The invention discloses a production route which is concise and green in route, low in cost and easy to industrialize to prepare 2,4-difluorobenzylamine. The route comprises the following four steps:a) by taking m-difluorobenzene as an initial raw material, under catalysis of lewis acid, carrying out a Foucault alkylation reaction with ethylene oxide so as to prepare an intermediate 2,4-difluorobenzene ethanol; b) carrying out a second step of reactions on the product of the step a) without separation or purification, and oxidizing the 2,4-difluorobenzene ethanol to generate 2,4-difluorobenzene phenylacetic acid; c) enabling the product 2,4-difluorobenzene phenylacetic acid of the step b) with sulfoxide chloride and an ammonia gas to react so as to prepare 2,4-difluorophenylacetamide; d)under induction of bromine, enabling the product 2,4-difluorophenylacetamide of the step c) to react with a sodium hypochlorite solution, and carrying out Hofmann degradation, thereby obtaining a target product 2,4-difluorobenzylamine. The preparation method disclosed by the invention is simple and easy in raw material obtaining, concise in route, green and environmentally friendly, low in cost and easy in industrial production.