The invention relates to an industrial synthesis method of isopropyl tanshinol, which comprises the following step: in the presence of the second hydrochloric acid and a reducing agent Zn-Hg, beta-(3,4-dihydroxylphenyl)pyruvic acid reacts with isopropyl ester in a solvent to generate the isopropyl tanshinol, wherein the beta-(3,4-dihydroxylphenyl)pyruvic acid is obtained by hydrolyzing 2-methyl-4-(3,4-diacetoxylbenzal)oxazole in the first hydrochloric acid. In the method provided by the invention, esterification and modification reducing reaction are performed at the same time. The synthesis of an intermediate product tanshinol in a synthesis method is omitted, the process operation is simplified, and the production period is shortened. Moreover, since the beta-(3,4-dihydroxylphenyl)pyruvic acid is directly obtained by hydrolyzing 2-methyl-4-(3,4-diacetoxylbenzal)oxazole in the hydrochloric acid solution, the process operation is further simplified.