As a new type of clean energy, biodiesel has been paid more and more attention. According to the existing methods of preparing biodiesel by chemical method, there are many disadvantages such as long reaction time, high energy consumption and serious environmental pollution. A new type of continuous flow microwave reactor is designed for the preparation of biodiesel. The electromagnetic field, chemical reaction kinetics, laminar flow and heat and mass transfer are coupled with multiple physical fields to simulate the reaction process through Coｍsol Multiphysics. By analyzing the effect of reactant flow rate on temperature, and by analyzing the effect of coil turns, coil spiral size and cavity size on the energy utilization ratio, the overall reactor structure size is optimized to improve the energy utilization ratio and increase the handling capacity of the reaction materials.<考文献原文>S参INGH S P,SINGH D. Biodiesel production through the use of different sources and characterization of oils and their esters as the substitute of diesel:a review[J]. Renewable and Sustainable Energy Reviews, 2010,14(1):200-216.<考文献原文>魏明红,赵华.生物柴油制备方法及应用现状[J].当代化工, 2006,35(4):246-249. (WEI Minghong,ZHAO Hua. Preparation method and application status of biodiesel[J]. Contemporary Chemical Industry, 2006,35(4):246-249.)<考文献原文>袁红,刘慧昌.微波强化固体酸催化酯化反应[J].中国油脂, 2013,38(9):60-63. (YUAN Hong,LIU Huichang. Solid acid catalyzed esterification strengthened by microwave[J]. China Oils and Fats, 2013,38(9):60-63.)<考文献原文>王如意,徐会佳,茹世杰,等.磷酸银光催化降解甲磺酸吉米沙星的研究[J]. 太原科技大学学报, 2017,38(3):243-248. (WANG Ruyi,XU Huijia,RU Shijie,et al. Simulation of constant velocity flow of pure material dendritic growth using phase field method[J]. Journal of Taiyuan University of Science and Technology, 2017,38(3):243-248.)<考文献原文>张增强,孙楠,高锦明,等.微波辅助棕榈油制备生物柴油的研究[J].中国油脂, 2008,33(3):53-55. (ZHANG Zengqiang,SUN Nan,GAO Jinming,et al. Preparation of biodiesel from palm oil assisted by microwave[J]. China Oils and Fats, 2008,33(3):53-55.)<考文献原文>韩毅,邓宇,郝敬梅,等.NaOH催化微波法制备生物柴油的工艺研究[J]. 精细石油化工进展, 2008,9(1):38-41. (HAN Yi,DENG Yu,HAO Jingmei,et al. Research on preparation of biodiesel by NaOH base catalytic under microwave irradiation[J]. Advances in Fine Petrochemicals, 2008,9(1):38-41.)