The invention belongs to the technical fields of synthetic chemistry application and biomedicine, and in particular relates to a synthetic method of obeticholic acid. The method takes 1,4-nucleophilicaddition of a sulfur nucleophile to 6-ethylidene-7-ketogallstone acid and subsequent Raney Ni reduction reaction as core steps, avoids dangerous catalytic hydrogenation reaction, and has the advantages of mild reaction conditions, simple operation, low cost and the like.