The texture and sensory characteristics of gluten‐free steamed bread are highly dependent on the functional properties of protein, which can be improved by inducing the glycosylation reaction in protein‐polysaccharide mixtures. This study aimed to assess the impact of potato protein‐xanthan mixture (PX) and its glycosylated product (PXM) on the water state, rheological, specific volume and texture qualities of gluten‐free dough and steamed bread. The two mixtures were used to substitute for 0.5–2% of the flour in a trial gluten‐free steamed bread formulation. The specific volume (1.76 mL g−1) and hardness (13.40 N) of steamed bread with 2% PXM were significantly improved compared to those of the control (0.86 mL g−1, 19.17 N). Moreover, the addition of PX and PXM improved the water state, viscoelasticity and development height (Hm) of gluten‐free dough, especially PXM. The reason appeared to be related to that protein glycosylation modified the solubility, ζ‐potential, hydrophobicity and emulsion activity of potato protein. In conclusion, application of the glycosylated protein provides a potentially feasible approach to improve the quality of gluten‐free steamed bread.