Abstract: In order to obtain optimal process conditions for preparation of fuel oil by calcium oxide catalyzed by Jatropha curcas oil cracking，the three-factor and three-level orthogonal tests were carried out with reaction temperature，catalyst particle size and mass space velocity as experimental factors based on yield and acid value.The comprehensive equilibrium analysis of the test results showed that the optimal preparation conditions were reaction temperature 490 ℃，catalyst particle size 2.5~5 mm，and mass space velocity 1.56 h-1，under which the yield of liquid hydrocarbons could reach 64.38% and acid value of the product was 1.3 mg KOH/g.The acid value of the liquid product obtained by using calcium oxide as a catalyst was low，and its main components were olefins，alkanes and alcohols，which had good combustion performance.