Abstract: To investigate the effects of Lonicera japonica polysaccharide（LJP）on the frozen storage stability of frozen dough and the quality of pre-proofed red bean paste buns. Frozen dough samples were prepared with different levels of LJP (0, 0.5%, 1.0%, 1.5%, and 2.0%). Following freeze–thaw cycle treatment, the pasting, rheological, and thermal properties of the dough were evaluated, together with moisture migration and protein secondary structure. In addition, the texture, specific volume, color, electronic nose response, and sensory scores of the resulting red bean paste buns were analyzed. The results showed that LJP improved dough stability during frozen storage by binding water molecules through its hydrophilic groups, thereby mitigating ice crystal-induced damage to the gluten network and enhancing the water-holding capacity and structural integrity of the dough. At an LJP addition level of 1.5%, the dough exhibited the highest storage modulus (G') and loss modulus (G"), the greatest proportion of bound water, and increased contents of the more stable α-helix and β-sheet structures in the protein secondary structure. The gluten network at this level also showed the most compact and continuous microstructure. Correspondingly, the red bean paste buns prepared with 1.5% LJP displayed the highest specific volume and height-to-diameter ratio, reaching 1.28 mL g⁻¹ and 0.534, respectively, along with favorable textural characteristics. The addition of 1.5% LJP increase the contents of aromatic compounds and terpenoids, inhibit the production of undesirable volatile components. The highest sensory score (89.4) was also obtained at this level, indicating the best overall product quality. In contrast, excessive addition of LJP (2.0%) disrupted gluten network continuity and adversely affected product quality. Overall, these findings provide a theoretical basis and technical reference for the development of hydrocolloid-based quality improvers for frozen dough and suggest a promising new application of LJP in the industrial production of flour-based foods.