〔Abstract〕 Objective To analyze the application value of electrocardiogram in the diagnosis of coronary heart disease. Methods 206 suspected coronary heart disease patients admitted to Longyan First Hospital from January 2021 to June 2022 were included in the study. All patients underwent coronary angiography and electrocardiogram diagnosis, and the diagnostic efficacy of electrocardiogram was analyzed using coronary angiography as the gold standard. Results Out of 206 patients diagnosed by coronary angiography, 195 patients were diagnosed with coronary heart disease. The accuracy of electrocardiogram in diagnosing this disease was 97.57 % (201/206), specificity was 100.00 % (11/11), and sensitivity was 97.44 % (190/195). Conclusion Electrocardiogram can effectively diagnose coronary heart disease with high diagnostic efficiency. However, since electrocardiogram diagnosis of coronary heart disease is not intuitive, clinical features still need to be combined during diagnosis to further improve diagnostic efficiency.