Abstract: The experiment used fresh sweet potato as major raw material, processed by far infrared toast and applied testmethod to find parameters and the proper technology of making the biscuit of sweet potato. At the same time ,it studied thequality influence of the biscuit from ingredients. The biscuit recipe was taking cooked sweet potato as 100%( moisture 50%),wheat flour was added 30%, potato starch 5%, cassava starch 6%, corn starch 5%, NaH4HCO30.2% and NH4HCO3 0.2%;Besides ,hydrogenated oil was added5%, whole milk powder 5%, margarine 3% and egg 2% . All these could imporove thequality of appearance and the crisp degree of the sweet potato biscuit; The infrared ray toast parameters were :for the firststage, the toasts temperature was 95℃ and 70 min and for the second stage ,the toast temperature was 105℃ and 5 min.

Key words: Sweet potato , Crisp biscuit , Far infrared , Toast