Abstract: To investigate the ameliorative effects of egg yolk oil on dextran sulfate sodium（DSS)-induced acute ulcerative colitis（UC）in mice, ICR mice were randomly divided into normal control group, DSS model group, egg yolk oil low-dose group（2.5 mL·kg⁻¹), and high-dose group（5.0 mL·kg⁻¹). The mice were fed with egg yolk oil for 35 days followed by 7 days of DSS induction for UC. Body weight, disease activity index（DAI), colon length, organ indices, serum levels of inflammatory cytokines（TNF-α, IL-6, IL-1β, IL-10）and total bile acids（TBA）were measured, and colonic histopathological changes were observed. The results showed that compared with the DSS model group, the egg yolk oil-fed groups exhibited attenuated body weight loss, reduced DAI scores（P＜0.05), increased colon length（P＜0.05), and decreased swelling indices of the cecum, spleen, and liver（P＜0.05). Serum levels of pro-inflammatory cytokines TNF-α, IL-6, and IL-1β were decreased（P＜0.05), while the level of anti-inflammatory cytokine IL-10 was increased（P＜0.05); serum TBA content was also reduced（P＜0.05). Colonic pathological damage was markedly ameliorated. The high-dose group showed better effects than the low-dose group. In conclusion, egg yolk oil exerts ameliorative effects on DSS-induced acute UC in mice, and the underlying mechanism may involve regulation of inflammatory cytokine balance, improvement of bile acid metabolism, and repair of intestinal barrier function. These findings suggest a promising application prospect for egg yolk oil in the development of high-quality functional foods.