Pueraria was used to produce pueraria powder. Based on the single-factor tests, the blanching time, steaming temperature, steaming time and drying conditions were selected as independent variables, the iodine blue value was the response value. Optimized the vacuum drying process of pueraria powder by Box-Behnken response surface methodology, and then the quadratic regression equation was established. The optimum conditions were as follow: blanching time 155 s, steaming temperature 90 ℃, steaming time 9.5 min, drying temperature 63 ℃ and drying time 8.3 h. Under the above conditions, the free starch′s iodine blue value of pueraria powder was 7.62, the relative error is about 1.7% to the predicted value of 7.75. This indicated that the regression model obtained by response surface was reliable and practical. Furthermore, the puerarin powder made by the optimized vacuum drying process, compared with hot air drying and vacuum freeze drying, had better saved nutrient contents and balanced with higher nutritional value, which is also has a good processing characteristic . It has practical application value in the production and development of pueraria powder.