Abstract: To explore the potential application value of soy oligopeptides (SOP) in wheat bread, low-field nuclear magnetic resonance spectrometer, rheometer, scanning electron microscopy (SEM), and Fourier-transform infrared spectrometer (FTIR) were used to investigate the effects of SOP (replacing wheat flour at 0.2%, 0.4%, 0.6%, 0.8%, and 1%) on the moisture distribution, rheological properties, microstructure, and secondary structure of protein in wheat dough. After baking the dough into bread, the effects of SOP on the specific volume, porosity, textural properties, and relative crystallinity of the bread were investigated. The results showed that when the replacement amount of SOP was 1%, compared with the blank control group, the free water content in the dough decreased by 1.71% (P<0.05), indicating that SOP effectively reduced the free water content and promoted its transformation into tightly-bound water and semi-bound water. Rheological analysis revealed that the addition of SOP reduced the G' and G" values of the dough and increased its viscosity. Infrared showed that SOP increased the total content of ordered structures (β-sheets and α-helixes) by up to 7.35%, suggesting a promotion of dough protein transformation from disordered to ordered conformations. The addition of SOP significantly increased the specific volume and porosity of bread and reduced its hardness (P<0.05). When the substitution level was 0.4 %, the hardness of the bread decreased by 42.27% compared to the control group, and the relative crystallinity by 1.16 % compared with the control. At this substitution level, the bread exhibited a more homogeneous and finer cellular structure, accompanied by a softer and more palatable texture.