Abstract: Natural inulin is a naturally occurring dietary fiber polysaccharide, which has physiological effects such as improving human intestinal health, lowering blood lipids, anti-inflammation and anti-colorectal cancer. Dry inulin is an amorphous powder, similar to the color of flour, so compared with other types of dietary fiber, it is more advantageous in improving the quality of flour products. In order to explore the effect of natural inulin on the processing characteristics of common wheat flour, this study used common commercially available wheat flour as the material, and 0, 1, 2, 3, 4 and 5 (g/100 g) level of natural inulin was partially substituted for wheat flour to prepare composite powder. Then, the influence of natural inulin on the gluten aggregation characteristics of wheat flour was analyzed using Gluten Peak Tester. The results showed that with the increase of the amount of natural inulin, the maximum peak time of flour gradually increased, the water absorption rate decreased from 54.4% to 52.4%, and the aggregation energy decreased from 960.6 GPI to 833.7 GPI, but there was no significant change in the loss of Torque 120 s after Maximum Torque. The texture analyzer was used to analyze the influence of natural inulin on the texture properties of the dough. The results showed that with the increase of the amount of natural inulin, the chewiness and hardness of the dough gradually decreased, and the stickiness and tackiness decreased significantly. Resilience and elasticity had no significant changes, but cohesiveness increased to the maximum with the addition amount of 3 g/100 g and 4 g/100 g, respectively. Next, a confocal laser scanning microscope was used to analyze the influence of natural inulin on the microstructure changes of gluten protein in the dough. The results showed that when the addition of natural inulin was 5 g/100 g, the network structure of gluten protein in the dough was denser, and the association between starch and protein became tighter. In brief, when 5 g/100 g of natural inulin was added, it can interact with flour and water. As competing with protein for water molecules, natural inulin can also combine with protein through hydrogen bonds and hydrophobic interactions, thereby changing the internal structure and the distribution of water in the dough, improving the elasticity and the chewiness of the dough.