Abstract:To develop a high-fiber biscuit，low-gluten flour，purple yam puree，and oat flour were used as main raw materials to make sugar-freepurple yam oat biscuit.Sensory score and maximum shear rate were used as indictors，to investigate the effect of purple yam puree，oat flour，oil，milk and xylitol powder addition on the quality of biscuits，the best formula and process for making biscuits were determined by orthogonal experiment.Based on the 100% addition of mixed flour（low-gluten flour and oat flour），the results showed that the optimal process conditions were 60% of low-gluten flour，40% of oat flour，50% of purple yam puree，40% of xylitol，40% of oil，4% of milk powder，4% of egg liquid 4% ，0.3% of salt，1.5% of baking soda，0.8% of monoglyceride and 0.2% of citric acid，baking for 12 min at 160℃ of upper and lower fire.The biscuits made under this condition are compared with blank control biscuits，purple yam oat biscuits had the characteristics of high protein，low fat，and high fiber，and had better nutritional value.The starch hydrolysis index and estimated glycemic index of biscuits were 52.76 and 68.67 respectively，it belonged to medium glycemic index food.Adding purple yam and oat to biscuits delayed the digestion speed of starch.