Objective: To explore the effect of metoprolol succinate sustained-release tablets combined with Wenxin Granules in the treatment of coronary heart disease patients with arrhythmia. Methods: The research objects were 50 patients with arrhythmia who were treated in our hospital from September 2019 to September 2020. According to different treatment methods, they were divided into observation group (Wenxin Granule + metoprolol succinate treatment) and control group (metoprolol succinate treatment), 25 cases in each group. The curative effects of the two groups were compared. Results: After treatment, there was no significant difference in rnn50, RMSSD, sdnni and SDANN between the two groups (P>0.05). Compared with the control group, the SDNN in the observation group was higher than that in the control group (P< 0.05); Before treatment, there was no significant difference in the above indexes between the two groups (P>0.05); The effective rates of the observation group and the control group were 92.00% and 68.00% respectively, and the curative effect of the observation group was higher than that of the control group (P< 0.05); There was no significant difference in the incidence of adverse reactions between the two groups (P> 0.05). Conclusion: In the treatment of patients with coronary heart disease and arrhythmia, Wenxin Granule Combined with metoprolol succinate sustained-release tablets has significant effect, which can effectively improve the dynamic electrocardiogram indexes of patients, improve the clinical efficacy, and has high safety.