Abstract: An experimental study of biodiesel production in a self-made magnetically fluidized bed by superparamagnetic whole-cell catalyst was conducted. By changing the magnetic field strength, methanol to oil molar ratio, catalyst concentration, flow rate and other factors, effects of different factors on the continuous transesterification reaction had been found. The optimized factors of single-stage fluidized bed catalytic transesterification of waste oil were using magnetic steady-state operation, methanol to oil molar ratio of 1:1, quantity of catalyst with 12% of oil and the feed rate of 42.6 mL/min. The final methyl ester production rate of the four-stage continuous magnetically fluidized bed reactor system was over 85%. Even after 200 h continuous operation, the production rate of the forth export was more than 80 %.The results showed that the whole-cell catalyst in the magnetically fluidized bed had high activity and long service life, the system had a good operational stability.