The invention discloses a full-synthetic method of racemic tetrandrine, and belongs to the technical field of drug synthesis. The full-synthetic method of the racemic tetrandrine comprises the steps that a synthetic route adopts a convergence synthesis method, a 5-bromovanillin, namely a compound 1 and 3-hydroxy-4-methoxyphenylacetic acid, namely a compound 5 are taken as starting materials to obtain a compound 4 and a compound 6 respectively, then the compound 4 and the compound 6 are taken as raw materials to synthesize a compound 11, a compound 19 is synthesized from the compound 11, and finally, the compound 11 reacts with the compound 19. The full-synthetic method of the racemic tetrandrine has the advantages that the synthetic efficiency is higher, the yield is higher, and the cost is lower; the reaction conditions are milder, the operation is simple and convenient, the industrial value is higher, and a reference is provided for the full-synthetic method of optical voidness tetrandrine.