NOVELTY - An (iso)ascorbic acid ester derivative is produced by subjecting mixture comprising lower alcohol, organic acid, polyol, immobilized lipase and reaction solvent to transesterification to prepare organic polyol ester; filtering solid immobilized lipase, distilling to obtain organic polyol ester and retaining organic lower alcohol ester and polyol solid solution; adding solid solution with organic lower alcohol ester and filtering; washing filter cake with solvent, removing residual organic acid and lower alcohol ester to obtain polyol ester crude product, and crystallizing.    USE - Process of producing (iso)ascorbic acid ester derivative (claimed) useful in food, pharmaceutical and chemical industries.    ADVANTAGE - The process involves green production steps, can ensure complete separation of residual impurity, has zero discharge to obtain high purity product. The raw material conversion rate and product yield are high. The production cost is greatly reduced.    DETAILED DESCRIPTION - Production of (iso)ascorbic acid ester derivative comprises:    (A) preparing mixture comprising lower alcohol, organic acid, polyol, immobilized lipase and reaction solvent;    (B) subjecting mixture to transesterification to prepare organic polyol ester, and then continuously evaporating out lower alcohol from the reaction system;    (C) after ending reaction, filtering solid immobilized lipase, distilling to recover reaction solvent to obtain organic polyol ester and retaining organic lower alcohol ester and polyol solid solution;    (D) adding solid solution with organic lower alcohol ester and filtering to obtain polyol filter cake and recycling filter liquor;    (E) washing the filter cake with solvent, removing residual organic acid and lower alcohol ester to obtain polyol ester crude product, and circulating washing liquid after recycling solvent;    (F) filtering crude product to remove insoluble solid residue, then cooling and crystallizing; and    (G) filtering crystal, washing, and drying to obtain (iso)ascorbic acid ester derivative.