Dictyophora indusiata polysaccharide is an important bioactive component with the ability to promote probiotic proliferation and produce acetic acid. Here, the effects of Dictyophora indusiata polysaccharide on the stability and flavor of set yoghurt were investigated by an effective strategy during the low-temperature storage of 1, 7, 14 and 21 days. The results suggested that the addition of 0.1% (w/v) Dictyophora indusiata polysaccharide improved the water holding capacity, hardness, cohesiveness and chewiness of set yoghurt, which may be related to the enhancement of the 3D network structure of set yoghurt by Dictyophora indusiata polysaccharide. In addition, the production of glucose and lactic acid were improved in set yoghurt due to the unique microbial decomposition strategies of Dictyophora indusiata polysaccharide. In particular, 0.1% Dictyophora indusiata polysaccharide had no adverse effects on the flavor of set yoghurt. The study provides new insights into improving the stability of fermented dairy products with edible fungi polysaccharides and establishes the foundation for the high-value development of edible fungi polysaccharides in the food industry.