The invention belongs to the technical field of preparation of anti hepatitis C virus drug intermediates and particularly relates to a synthesis method of (1R, 2S)-1-amino-2-vinyl ethyl cyclopropane dicarboxylate. The synthesis method comprises the specific steps that step one, benzaldehyde, glycine ethyl ester hydrochloride, toluene and triethylamine are used as raw materials to be synthesized into a compound 4; step two, the compound 4 and trans-1,4-dibromo butene react in the toluene and sodium ethoxide to prepare a compound 3; step three, the compound 3 and (2S)-2-[(3,5-dichlorobenzoyl peroxide) oxy] propionic acid react in the toluene, and then isopropyl alcohol and hexane are added to obtain a compound 2; step four, the compound 2 reacts with sodium hydroxide in the toluene to obtain a compound (1R, 2S)-1-amino-2-vinyl ethyl cyclopropane dicarboxylate. The synthesis method is simple in operation and suitable for industrialized production, the raw materials are cheap and easy to obtain, and the obtained target product is high in purity and chiral purity.