This invention discloses a centrifuge molecular distillation method for producing biodiesel oil for internal combustion engines. The method comprises: (1) esterifying plant oil or animal oil or their mixture; (2) performing coarse-separation on the esterification products to obtain crude methyl ester or crude ethyl ester; (3) degassing and separating methanol or ethanol at 50-150 deg.C, 100-5000 Pa and 300-1000 rpm, and then separating methyl ester or ethyl ester at 100-250 deg.C, 1-50 Pa and 600-1400 rpm. The obtained biodiesel oil has purity higher than 98%, and can be used in internal combustion engines. The method has such advantages as simple process, no wastewater pollution and saved water treatment cost. |