In an effort to reduce the production cost of biodiesel and realize the lipase recovery of the in situ transesterification technology, a reactor with facile catalyst separation device was developed in this study. Compared with conventional method of biodiesel production, this improved reactive extraction. technology can realize not only the biodiesel synthesis in a single step, but also the separation of immobilized lipases from the oilseed residues easily. This technology may present a sustainable, economically attractive process for biodiesel production. J. curcas L. seed, methanol, Lipozyme TL IM, and cosolvent n-hexane were used in this study. The effect of various process parameters on the yield of fatty acid methyl esters (FAMEs) was investigated. The highest FAMEs yield of 90.6% could be achieved under the optimum conditions: n-hexane/seed ratio of 3.5:1 inL/g, methanol/oil molar ratio of 6:1, 15% (w/w) of Lipozyme TL IM, reaction temperature of 45 degrees C, water content of 1.0%, and reaction time of 12 h. The lipase could maintain more than 40% of its initial activity after 13 batches operation under optimal reaction conditions This simple in situ transesterification technology with facile catalyst separation device can be a potential route for biodiesel production, which may greatly reduce the processing steps and costs.