NOVELTY - Optically active compound of piperidine-2-formylaniline enriching involves mixing R-ropivacaine, bupivacaine, intermediate, inert solvent, initiator and thioalcohol to obtain a mixture. Mixture is stirred at 70-110 degrees C to perform racemization reaction for 2-10 hours to obtain reaction solution containing R- and S-ropivacaine, bupivacaine and common intermediate of N-(2,6-dimethylphenyl)-2-piperidinecarboxamide. An acid is added into the reaction solution to perform salt formation reaction. An organic solvent A is added in reaction solution to perform extraction and to separate organic phase.    USE - Method for enriching optically active compound of piperidine-2-formylaniline (claimed).    ADVANTAGE - The method is eco-friendly and improves the production efficiency of optically active compound of piperidine-2-formylaniline.    DETAILED DESCRIPTION - Optically active compound of piperidine-2-formylaniline enriching involves mixing R-ropivacaine, bupivacaine, intermediate, inert solvent, initiator and thioalcohol to obtain a mixture. The mixture is stirred at 70-110 degrees C to perform racemization reaction for 2-10 hours to obtain reaction solution containing R- and S-ropivacaine, bupivacaine and common intermediate of N-(2,6-dimethylphenyl)-2-piperidinecarboxamide. An acid is added into the reaction solution to perform salt formation reaction. An organic solvent A is added in reaction solution to perform extraction and to separate organic phase. An alkali is added into the aqueous phase to adjust pH to 8-13. An organic solvent B is added into the aqueous phase to perform extraction and rotating evaporation to obtain racemic mixture of ropivacaine and bupivacaine. Chiral resolving agent i.e. dibenzoyl-L-tartaric acid monohydrate and racemic mixture of ropivacaine and bupivacaine are kept in alcoholic solution to perform salt formation to obtain salt formation system. Ketone solution is added into the salt formation system to obtain mixed solution. The solution is filtered to obtain white solid and filtered solution. The white solid is dissolved in mixed solution to obtain a product. The white solid is dissolved in alkali to obtain a solution. The solution is extracted with organic solvent. The extracted solution is dried and evaporated to obtain single enantiomer of S-ropivacaine and S-bupivacaine. The filtered solution is reduced, and then the reduced solution is alkalized to obtain the finished product.