Chloroethylene carbonate (CEC) was prepared by chlorination of ethylene carbonate (EC) with sulfuryl chloride and azobisisobutyronitrile (AIBN) as an initiator. CEC reacted with Potassium fluoride (KF) as a fluorinating agent in a solution to give Fluoroethylene Carbonate (FEC). The optimum technological conditions for preparing CEC were as follows: the reaction taken place at 65℃; sulfuryl chloride was added into the reaction solution in drops in 72min and reacted for 1.5h, the molar ratio of ethylene carbonate(EC) and sulfuryl chloride was 1:1.3, the amount of substance ratio of AIBN and EC was n（AIBN）：n（EC）=1:200. The yield could be reached to 85.81% under such reaction conditions. The optimum technological conditions for preparing FEC were as follows: acetonitrile was chosen as the solvent, the reaction temperature was 75℃, the reaction time was 1.5 to 2h, the molar ratio of CEC and KF was1:1.3. Under these reaction conditions, the yield can be reached to 71.86%. The product was characterized by IR and GC-MS.