Abstract: In order to optimize the high temperature short time air puffing technology of adlay, the experiments were conducted by response surface methodology to investigate the effects of four influencing parameters of pre-gelatinization time, puffing temperature, puffing time and water content on expansion rate and yellow-blue index . In vitro digestion of starch and protein, and cell structure of adlay before and after puffing were also analyzed. The results showed that the importance of affecting factors were in the order of the puffing time, water content, puffing temperature and pre-gelatinization time. The optimum conditions were that pre-gelatinization time of 29.9 min, puffing temperature of 251℃, puffing time of 20.0 s and water content of 6%. After puffing, the external digestion of starch and protein of adlay increased significantly (P<0.05). Cell structure of adlay showed honeycomb structure, and there were many big cavities. The research can provide a method for shortening cooking time and improving nutrient digestion and absorption rate of adlay, which can meet the requirements of industrial production.