A Central Composite Design was adopted to optimize the technology for freezing-Vacuum drying of fava beans. Effect of three variables of water content in raw material,Vacuum drying temperature and vacuum drying time on water content of final product,puffing rate and color were investigated. Based on the experimental data,the quadratic regression model of three indexes was established,then variables were analyzed with response surface methodology( RSM). The result showed that all three factors showed significant influences on the three indexes. The optimal technical conditions were obtained as follows: water content after freezing was 50%,Vacuum drying temperature was 85℃ and vacuum drying time was 120min.