NOVELTY - A chiral (S)-2chloropropionic acid preparing method involves adding racemic 2-chloropropionic acid and R-chiral N-benzyl-phenylethylamine resolving agents to an alcohol solvent, heating the obtained mixture, and cooling at 0-5 degrees C for generating (S)-2chloropropionic acid and (R)-2chloropropionic acid organic amine salt precipitates. The precipitates are filtered to obtain filtrate and filter cake. The filtrate is distilled. The alcohol solvent is recycled from the distilled filtrate for obtaining the (S)-2chloropropionic acid.    USE - Method for preparing chiral (S)-2chloropropionic acid.    ADVANTAGE - The method enables avoiding environmental pollution caused by laminopropionic acid, enables recycling the resolving agents and the detached (R)-2-chloropropionic acid after being racemized, reducing generation of wastes, achieving energy conservation, environment friendliness, emission reduction and consumption reduction, reducing production cost and improving market competition of the product. The obtained product is favorable in industrial prospect. The (S)-2chloropropionic acid obtained by the method is good in purity and high in chiral purity.    DETAILED DESCRIPTION - A chiral (S)-2chloropropionic acid preparing method involves adding racemic 2-chloropropionic acid and R-chiral N-benzyl-phenylethylamine resolving agents to alcohol solvent, heating the obtained mixture, and cooling at 0-5 degrees C for generating (S)-2chloropropionic acid and (R)-2chloropropionic acid organic amine salt precipitates. The precipitates are filtered to obtain filtrate and filter cake. The filtrate is distilled. The alcohol solvent is recycled from the distilled filtrate for obtaining the (S)-2chloropropionic acid or the precipitates are filtered to obtain filtrate containing (R)-2chloropropionic acid and filter cake. The filter cake is dispersed in the alcohol solvent and supplied hydrogen chloride gas for acidification to the alcohol solvent for dissociating the (S)-2-chloropropionic acid. The (S)-2-chloropropionic acid is filtered for obtaining filter cake of S-chiral N-benzylphenylethylamine hydrochloride and the filtrate containing (S)-2chloropropionic acid. The filtrate is distilled. The organic solvent is recycled from the filtrate for obtaining the (S)-2chloropropionic acid by distilling.