Reconstituted noodles containing multi-grain are superior to plain noodles in terms of health benefits, but their lower gluten levels cause deterioration in cooking performance and textural quality. To this end, this study investigated the efficacy of gluten pre-hydration in a model dough. The results indicated that, with the increase in the ratio of pre-hydrated gluten, the final hydration level of gluten in reconstituted noodles, the proportion of ordered secondary structures of gluten, and the intensities of molecular interactions continuously increased, resulting in a more compact gluten network. This made the dough more deformable, granting noodles higher cooking resistance (optimal cooking time: 230 s to 265 s) and hardness (1837 g to 2538 g). Gluten pre-hydration was more effective, convenient, and cost-efficient than existing methods in improving the quality of reconstituted noodles. However, it lowered the yield and transparency of cooked noodles and made them yellowish.