For more efficient and environmental friendly production of biodiesel from high acid value oil, a simple method was developed and investigated to produce biodiesel by combination of gaseous esterification and solid acid catalyst, and the waste cooking oil fatty acid was taken as the reactant. The orthogonal test was used to plan the experiments and optimize the reaction conditions, catalyst loading, reaction time and temperature, and the optimal conditions were obtained, 15% catalyst dosage, 60min reaction time and 105℃ reaction temperature. Under these conditions, the catalyst could be reused for 5 times, and the acid value of biodiesel was only 0.64mg/g. The reaction rate of esterification could reach to 99.65%, and the quality of refined biodiesel could meet the national standard GB/T20828—2007.