The invention relates to a preparation method of chiral 4-substituted oxazolidone, which belongs to the pharmaceutical chemistry technical field. Chiral amino acid ester or chiral amino acid ester salt is added into a solvent, supercarbonate is charged, chloro formate is titrated at the room temperature, and mixed for 5 to 8 hours at the room temperature after titration is completed, filtering isperformed, and the solvent is recovered to obtain an intermediate compound a; the intermediate compound a is adopted in an anhydrous chloride solution for accelerating the catalyst of borohydride, reaction is performed for 4 to 10 hours at 0 to 40 DEG C, the solvent is recovered, a citric acid solution is added, extraction is performed by using ethyl acetate, an organic layer is combined, the solvent is recovered, and then an intermediate compound b is obtained; potassium carbonate is added into the intermediate compund b, heating, back flow and water diversion are performed for 2 to 4 hours,pump filtering is performed before cooling down, the filter liquor is cooled and recrystallized, pump filtering and drying are then performed to obtain a white crystalline solid 4-substituted chiral oxazolidone chemical compound. The invention provides the preparation method of a 4-substituted chiral oxazolidone chemical compound, the invention aims at the problem of significant safe hidden danger caused when phosgene is adopted for acidylation and cyclization in the prior art.