Abstract: Dietary alkali is a kind of food additive, which can increase the flavor of noodles and neutralize gastric acid. In this study, the effect of dietary alkali with different additive amounts (0%, 0.1%, 0.2%, 0.3%, and 0.4%) on protein aggregation behavior was evaluated by measuring the protein intermolecular forces and the content of glutenin macropolymer and observing the apparent morphology of protein. Noodle quality was analyzed by cooking characteristics, texture properties, and sensory evaluation. The results showed that dietary alkali promoted the conversion of the free sulfhydryl groups into disulfide bonds, increased the number of hydrogen bonds and decreased the hydrophobic interactions in the dough, enhancing the content of glutenin macropolymer. AFM results showed that dietary alkali induced the wheat gluten protein chains strongly interwove, forming a roughly spherical shape. Whereas, those chains in the wheat gluten without dietary alkali were less interwoven, completely collapsed, and relatively flat manner. With the increase of dietary alkali addition, the water absorption of the noodles reached the maximum when the addition amount was 0.2%. However, the cooking loss, hardness, and chewiness of the noodles increased significantly. The elasticity of the noodles was not altered by alkali addition. As for sensory evaluation, a higher amount of dietary alkali darkened the color of the noodles and disturbed the taste. Therefore, the optimal addition of dietary alkali recommended in noodles was 0.2%.