In the present study, effect of deamidation by protein glutaminase (PG; EC 3.5.1.44) on structure of wheat gluten (WG) and its possible to construct high internal phase emulsions (HIPEs) system were investigated. The deamidation reaction was performed for different durations (0–48 h). The deamidation degree (DD, 0–70.5%) of WG was increased with an increase of reaction time (0–48 h). After the specific deamidation by PG, the solubility of WG was significantly improved at neutral pH while maintaining its molecular weight. Unlike native WG, deamidated WG (DWG) had the ability to form stable HIPEs. Moreover, HIPEs prepared using DWGs with a moderate DD (28.7–40.5%) exhibited remarkable characteristics in terms of their network structure, rheological behavior and friction coefficient. This study demonstrated the application of PG-modified WG for HIPE preparation and characterized their structural and functional relationship, providing a promising approach for the production of stabilized emulsions in food systems.