Epoxidized fatty acid methyl esters was synthesized by epoxidation in pipeline reactor by a continuous process with high concentration of 70% hydrogen peroxide，many disadvantages of the traditional batch process in tank reator were overcomed. The influencing factors on the epoxy value of the product，such as amount of H2O2， amount of HCOOH，reaction time，reaction temperature were discussed. The optimum conditions were determined as follows：m(fatty acid methyl esters)：m(H2O2) ：m(HCOOH)= 1∶0.6∶0.05，reaction time 15min，reaction temperature 90℃，The epoxy value of the product was up to 6.0% under these conditions.