Abstract: In order to investigate the effect of endogenous components on the digestive characteristics of multigrain mixed noodles with low glycemic index (GI), the noodles were first prepared from buckwheat, yam, high-amylose corn starch and wheat flour, and the GI value was 53.02. On this basis, the endogenous components such as phenols, lipids, proteins and dietary fibres were removed from the raw flour of noodles and then prepared separately into noodles for in vitro simulated digestion. The effects of the endogenous components on the starch hydrolysis rate, protein digestibility and colonic fermentation of the noodles were investigated, as well as their mechanisms of action. The results showed that the starch hydrolysis rate of noodles prepared after the separation of endogenous components increased significantly, and the estimated glycemic index (eGI) was as follows: Defatted noodles (68.76)>deproteinised noodles (67.94)>dietary-fiber-free noodles (63.62)>dephenolised noodles (60.16)>low GI noodles (53.02). The protein digestibility of noodles was as follows: Dietary-fiber-free noodles (65.04%)>low GI noodles (33.71%)>dephenolised noodles (17.55%)>defatted noodles (6.61%). Compared with wheat noodles, the resistant starch in multigrain mixed with low GI noodles significantly increased the content of short-chain fatty acids (SCFAs) in colonic fermentation stage, which contributed to the host's regulation of glucolipid metabolism, energy metabolism and energy supply.