Abstract: In order to reduce the glycemic index (GI) of miscellaneous grain biscuits and provide consumers with more choices of sugar-controlled foods, self-made miscellaneous grain biscuits mainly made from whole wheat flour, white barley, and black tartary buckwheat were studied. The effectiveness of different low-temperature baking methods in reducing the predicted glycemic index of biscuits was studied using in vitro simulated digestion methods. X-ray diffraction and scanning electron microscopy were applied to observe the changes in the microstructure of biscuits caused by low-temperature baking. The formula for low-temperature baked biscuits was: 30 g whole wheat flour, 60 g white barley flour, 10 g black buckwheat flour, 40 g butter, 10 g white sugar, 10 g maltitol, 20 g whole egg liquid, and 10 g pure milk. The baking conditions were controlled at 90 ℃ for 3 hours+160 ℃ for 10 minutes, 90 ℃ for 5 hours+160 ℃ for 8.5 minutes, 90 ℃ for 7 hours+160 ℃ for 5 minutes, and 160 ℃ for 18 minutes, respectively. The results showed that compared with biscuits baked at 160 ℃ for 18 minutes, low-temperature baking treatment can reduce the starch hydrolysis rate of biscuits at various time points. After low-temperature baking treatment, the predicted glycemic index (eGI) of biscuits can be reduced from 57.4 to 47.6. Microscopic observation showed that low-temperature baking affected the uniformity of the biscuit surface and increased the relative crystallinity of the biscuit starch, but did not change the crystal form. The sensory evaluation results showed that the biscuits made by low-temperature baking were superior to ordinary biscuits in terms of color, aroma, taste, and overall preference. Therefore, the low-temperature baking method could help to further improve the glycemic response of miscellaneous grain biscuits and is a candidate processing method for developing glycemic stabilizing biscuits.