Objective To analyze the influence of different health-related indicators on the prognosis of elderly patients with diabetes mellitus complicated with coronary heart disease, and to provide theoretical basis for the diagnosis and treatment of diabetes mellitus complicated with coronary heart disease. Methods Among of 456 elderly patients with diabetes mellitus complicated with coronary heart disease admitted to our hospital from December 2018 to December 2020 were selected. According to the occurrence of Major adverse cardiovascular events (MACE) within 1 year after discharge, patients were divided into the control group (no MACE) and the observation group (MACE). The Clinical data of patients including age, gender, BMI, smoking, alcohol consumption, diabetes course, degree of coronary artery stenosis and number of lesions, were collected from the medical record system. Univariate analysis and logistic regression were used to analyze the influence of health indicators such as systolic blood pressure, LEVF, HbA1c, LDL-C, LDH and ALP on the occurrence of MACE in patients with diabetes and coronary heart disease. Spearman correlation analysis was used to analyze the correlation between different health-related indicators and the occurrence of MACE in elderly patients with diabetes mellitus and coronary heart disease. Results A total of 456 elderly patients with diabetes mellitus and coronary heart disease, 122 cases (26.75%) developed MACE. There were no differences in age, male proportion, BMI, smoking and drinking of diabetes course between the two groups (P>0.05). The degree and number of coronary artery stenosis in the observation group were significantly higher than those in the control group (P<0.05). There were significant differences in HbA1c, LEVF, LDL-C, TC, TG and BUA between the two groups (P<0.05). HbA1c>7.0% (OR=2.617), LDL-C>2.6 mmol/L (OR=2.976) and BUA >420μmol/L (OR=2.341) were independent risk factors for MACE in elderly patients with diabetes mellitus and coronary heart disease (P<0.05). Spearman correlation analysis showed that HbA1c, LDL-C, BUA were positively correlated with MACE in elderly patients with diabetes mellitus and coronary heart disease (r=0.401,0.427,0.372, P<0.05). Conclusion Elderly patients with diabetes mellitus complicated with coronary heart disease have a higher risk of MACE, which is closely related to health-related indicators. For patients with HbA1c >7.0%, LDL-C >2.6 mmol/L and BUA >420 μmol/L, active treatment should be conducted to improve the prognosis of patients.