Biodiesel preparation from Jatropha oil catalyzed by KF/Red mud (KF/RM) was studied. The optimum values of parameters for preparation of Jatropha oil biodiesel were obtained. The conversion rate of transesterification reached 92.2% under the optimum conditions, and the used KF/RM could be regenerated. Catalyst characterization showed that KOH and KFeF4 were produced in KF/RM catalyst, which was crucial for the transesterification of Jatropha oil with methanol. Red mud was a good support to prepare KFloaded catalyst, and prepared KF/RM was an excellent catalyst for biodiesel synthesis from Jatropha oil via transesterification reaction.