〔Abstract〕 Objective To analyze the effects of metoprolol plus amiodarone on arrhythmia and cardiac function in patients with coronary heart disease. Methods A total of 100 patients with coronary heart disease and arrhythmia diagnosed and treated in Xiuyu District Hospital of Putian City from January 2019 to December 2021 were retrospectively selected as the research objects. According to different treatment plans, they were divided into a control group and an observation group, with 50 cases in each group. The control group was treated with amiodarone, while the observation group was treated with metoprol plus amiodarone. The effects of treatment on arrhythmia and cardiac function were compared between the two groups. Results The total effective rate of the observation group was 94.00 %, higher than 72.00 % of the control group, and the difference was statistically significant (P < 0.05). After treatment, the attack frequency of arrhythmia in the observation group was lower than that in the control group, and the duration of arrhythmia attack was shorter than that in the control group, the differences were statistically significant (P < 0.05). After treatment, cardiac function indexes in the two groups were decreased compared with before treatment, and cardiac function indexes such as QT dispersion (QTd), left ventricular end diastolic dimension (LVEDD), left ventricular end systolic diameter (LVESD) in the observation group were lower than those in the control group, the differences were statistically significant (P < 0.05). Conclusion Metoprolol and amiodarone in the treatment of coronary heart disease arrhythmia can improve the arrhythmia attack and cardiac function, improve the therapeutic effect.