Abstract: Objective To explore the relationship between arrhythmia detected by dynamic electrocardiogram and coronary artery lesions of different degrees in patients with myocardial infarction. Methods A total of 200 patients with acute myocardial infarction who underwent dynamic electrocardiogram and coronary angiography were selected as research objects, their incidence rates of arrhythmia were recorded. According to the results of coronary angiography, they were divided into different groups. The relationships between the number of coronary artery lesions, lesion location as well as stenosis degree and arrhythmia were analyzed. Results Among the 200 patients with acute myocardial infarction, there were 137 patients(68.50%)with atrial arrhythmia and 81 patients(40.50%)with ventricular arrhythmia, 132 cases(66.00%)with ST segment elevation, 53 cases(26.50%)with ST segment reduction, and 15 cases(7.50%)with no ST segment excursion. The incidence of frequent ventricular premature beats in the multiple-vessel lesion group was significantly higher than that in the single-vessel lesion group, and the incidence rates of premature ventricular beats of grade Lown3 and above, bradyarrhythmia, and atrial arrhythmia were significantly higher than that in the single-vessel lesion group and the multiple-vessel lesion group(P<0.05). The incidence of frequent ventricular premature beats and atrial arrhythmia in the left main and anterior descending branches group was significantly higher than that in the right coronary artery group, the incidence of ventricular premature - beats at grade Lown3 and above was higher than that in the left cyclobrane group and the right coronary artery group, and the incidence of bradyarrhythmia was significantly lower than that in the left cyclobrane group and the right coronary artery group(P<0.05). The incidence of ST-segment elevation in the group with stenosis of coronary artery more than 90% was significantly higher than that in the groups with stenosis of coronary artery less than 70% and ranging from 70% to 90%, and the incidence of ST-segment reduction was significantly higher than that in the group with stenosis of coronary artery ranging from 70% to 90%(P<0.05). Conclusion Arrhythmia is a frequently occurring disease in patients with acute myocardial infarction, and is closely related to coronary artery disease. The judgment of arrhythmia detected by dynamic electrocardiogram is beneficial to the prediction of coronary artery disease and prognosis of patients with acute myocardial infarction.