The invention belongs to the field of medicine and chemical industry, and concretely relates to a preparation method of an Abemaciclib intermediate. Nitro and carbonyl of 5-(4-ethyl piperazine-1-carbonyl)-2-nitropyridine are reduced successively, and the Abemaciclib intermediate 5-(4-ethyl-piperazin-1-yl)methyl)pyridin-2-amine is obtained; the raw materials and reagents are easy to obtain, reaction conditions are mild, usage of reagents with toxicity or irritation or strong corrosivity is avoided, the method is green and environmentally friendly, and the preparation is simple and easy to operate; the product has high yield and high purity, and is especially suitable for industrial production.