This experiment synthesize a rare-SO42-/ZrO2 solid acid catalyst, and investigate the optimal reaction conditions for the catalytic reaction of the catering waste oil and methanol reaction which is preparation for biodiesel. Under a condition of alcohol oil molar ratio of 9:1, a catalyst amount of 4 %, reaction time of 8 h, and reaction temperature of 240 degrees C, more than 65% of biodiesel yield was obtained. Each performance index of the Biodiesel can reach the standard of similar foreign products, and the prepared catalyst has good reusability.