Objective This paper aims to study the effect of ferulic acid (FA) on the aggregation behavior of glutenin subunits and the quality of steamed bread.Methods The interaction behavior between FA and gluten subunits with high relative molecular weight (HMW-GS) and gluten subunits with low relative molecular weight (LMW-GS) was compared to clarify the effect and mechanism of FA addition on the aggregation of gluten subunits.Results Adding FA with a mass fraction of 0.5% can effectively promote the aggregation of HMW-GS and LMW-GS, induce the oxidation of free thiol groups to form more disulfide bonds, increase the average particle size of protein aggregates, and enhance the content of stable α-helices and β-folds. It can also reduce the content of disordered random curls, promote the formation of HMW-GS and LMW-GS aggregates, further lead to the burial of hydrophobic groups, alleviate their surface hydrophobicity, and form a more stable tertiary structure. Adding 0.5% FA can induce more aggregation of HMW-GS than LMW-GS. HMW-GS+0.5% FA can effectively improve the quality of steamed bread. Compared with the original flour, the specific volume increases by 29.62%, and the hardness decreases by 18.59%.Conclusion HMW-GS+0.5% FA can effectively improve the quality of steamed bread.