Synthetic method of sofosbuvir intermediate

The invention provides a synthetic method of a sofosbuvir intermediate, wherein the method, with a compound (II) as an initial raw material, includes the steps of: 1) performing a de-protective reaction and a cyclization reaction to the compound (II) to obtain an inter-product (VIII); 2) performing esterification to the inter-product (VIII) with benzoyl chloride to obtain an inter-product (IX); and 3) dissolving the inter-product (IX) in a solvent, and slowly adding dropwise a sulfonyl chloride solution in the presence of organic alkali and triethylamine trihydrofluoride, wherein in the reaction process, the compound (X) serves as an intermediate and is unnecessary to separate, so that a fluoronation reaction thereof can be completed directly in the reaction system, thereby producing the sofosbuvir intermediate.