NOVELTY - An S-2-(4-nitrophenyl)ethylene oxide is prepared by culturing strain with halohydrin dehalogenase activity and epoxide hydrolase activity in culture medium to produce high activity halohydrin dehalogenase and epoxide hydrolase, dissolving racemic nitro bromoacetophenone and sodium borohydride in methanol, stirring, reacting in ice bath for 3 hours, adding water when reaction is complete, extracting using ethyl acetate, keeping organic phase, drying over magnesium sulfate (MgSO4), evaporating in rotary evaporator to obtain orange solid, and dissolving in N,N-dimethyl formamide.    USE - Preparation of S-2-(4-nitrophenyl)ethylene oxide for chiral pharmaceutical intermediate.    ADVANTAGE - Preparation method is environment-friendly and convenient, has high product yield and purity, strong enzyme stereoselectivity, high catalytic efficiency, reduced cost, and mild reaction conditions, speeds up production rate, and greatly reduces acid consumption.    DETAILED DESCRIPTION - An S-2-(4-nitrophenyl)ethylene oxide is prepared by culturing strain with halohydrin dehalogenase activity and epoxide hydrolase activity in culture medium to produce high activity halohydrin dehalogenase and epoxide hydrolase, dissolving racemic nitro bromoacetophenone and sodium borohydride in methanol, stirring, reacting in ice bath for 3 hours, adding water when reaction is complete, extracting using ethyl acetate, keeping organic phase, drying over magnesium sulfate (MgSO4), evaporating in rotary evaporator to obtain orange solid i.e. racemic 2-bromo-1-(4-nitrophenyl)ethanol and racemic 2-(4-nitrophenyl)ethylene oxide mixture with ratio of 7:3, dissolving mixture in N,N-dimethyl formamide, adding wet thalli or enzyme liquid with halohydrin dehalogenase activity and epoxide hydrolase activity, adding 6.8-8 pH phosphate buffer solution in reaction system, performing double-phase enzymatic reaction at 25-45 degrees C, and separating conversion product using ultrafiltration and extraction combined method.