Objective To analyze the influencing factors of digestive system damage after chemotherapy in elderly patients with breast cancer, and explore the correlation between digestive system damage and quality of life. Methods A total of 90 elderly patients with breast cancer admitted to our hospital from August 2019 to April 2023 were enrolled. Their clinical data, including basic information, tumor features, drug use, biochemical indicators and other indicators were collected. According to the severity of digestive system damage, they were divided into severe group (moderate to severe, n=27) and non-damage group (no or mild damage). World Health Organization quality of life scale-100 was applied to evaluate their quality of life. SPSS 26.0 was used for statistical analysis. Univariate and multivariate logistic regression were employed to analyze the influencing factors for digestive system damage in these elderly patients. Spearman correlation analysis was conducted to evaluate the correlation between the damage and quality of life of patients. Results Significant differences were observed between the severe group and the non-damage group in terms of age, hypertension, course of breast cancer, tumor node metastasis stage and chemotherapy course (all P<0.05). Multivariate logistic regression analysis showed that age (OR=2.815,95%CI 1.268-6.251) and duration of chemotherapy (OR=2.675,95%CI 1.255-5.701) were the influencing factors of digestive system damage in the patients (P<0.05). The quality of life score was (53.81±4.76) in the elderly breast cancer patients after chemotherapy. Spearman correlation analysis indicated that digestive system damage was negatively correlated with quality of life of the patients (r=-0.741, P<0.05). Conclusion There are many factors affecting digestive system damage in elderly patients with breast cancer after chemotherapy. More attention should be paid to those with high risk factors in clinical practice.