Abstract： Objective:To study the application of hyperbaric oxygen (HBO) combined with out-of-hospital continuing nursing based on three-dimensional quality evaluation model in patients with ulcerative colitis, and investigate the factors influencing patients’ quality of life.Methods:All research objects were treated with HBO in Yan’an University Affiliated Hospital. The patients ( n=60) with ulcerative colitis treated from January 2018 to December 2018 were selected as the control group; while the patients ( n=60) treated from January 2019 to December 2019 were selected as the observation group. The control group received the conventional out-of-hospital continuing nursing, while the observation group received out-of-hospital continuing nursing based on three-dimensional quality evaluation model. The nursing time for both groups were three months. The negative emotions, quality of life, and self-care ability of the two groups were compared, and the risk factors affecting the quality of life were analyzed. Results:After nursing, the Zung self-rating anxiety scale (SAS) and Zung self-rating depression scale (SDS) scores of the two groups decreased significantly, and the observation group decreased more significantly than the control group in terms of the SAS scores (33.14±3.86 vs. 43.55±3.77) and the SDS scores (35.47±2.95 vs. 45.46±3.46), and the differences were statistically significant ( P<0.05). The physical functioning ( t=2.563, P=0.012), role physical ( t=3.539, P=0.001), bodily pain ( t=2.448, P=0.016), general health ( t=5.301, P<0.001), vitality ( t=2.489, P=0.014), social functioning ( t=3.860, P<0.001), role emotional ( t=5.883, P<0.001), mental health ( t=3.729, P<0.001), and other indicators of the observation group were significantly higher than those of the control group. After nursing, the assessment scores of drug dependence, psychological adjustment ability, sleep quality, diet adjustment, and pain recognition in the observation group were significantly higher than those in the control group; the differences in quality of life assessment involving gender, education level, monthly income, marital status, mental status, exercise, lifestyle, drinking, smoking, and comorbid chronic diseases between the two groups were significant ( P<0.05); through multivariate analysis, gender, education level, monthly income, marital status, mental status, exercise, lifestyle, drinking, smoking, and comorbid chronic diseases were independent risk factors affecting the quality of life of patients. Conclusion:HBO combined with out-of-hospital continuing nursing based on three-dimensional quality evaluation model is of positive influence on the negative emotions and quality of life of patients with ulcerative colitis. And it is suggested high attention be paid to unmarried patients, and the patients with low monthly income, severe negative emotions, low education level, and chronic diseases.