Objective:To explore the effect of nursing based on Peplau's interpersonal relationship theory in rectal cancer patients with permanent colostomy.Methods:From January 2019 to December 2020, convenience sampling was used to select rectal cancer 90 patients with permanent colostomy in the Affiliated Hospital of Shaoxing University as the research object. The patients were divided into the control group and the observation group by random number table method, with 45 cases in each group. The control group was given routine nursing, and the observation group received nursing based on Peplau's interpersonal relationship theory. The Self-efficacy Subscale of the Chronic Disease Self-management Measuring Scale and the City of Hope-Quality of Life-Ostomy Questionnaire-Chinese Version (COH-QOL-OQ) were used to evaluate the intervention effect.Results:After the intervention, the scores of each item of the Self-efficacy Subscale and the total COH-QOL-OQ score of the observation group were higher than those of the control group, and the differences were statistically significant ( P<0.05) . Conclusions:Nursing based on Peplau's interpersonal relationship theory can improve self-efficacy and quality of life in rectal cancer patients with permanent colostomy.