Objective <p>To explore the clinical efficacy of nicorandil in treating elderly angina pectoris with diabetes mellitus (DM) and coronary heart disease (CHD), and the effect on improving vascular endothelial function (VEF).</p> Methods <p>110 elderly diabetic patients with CHD and angina pectoris who were treated in our hospital from April 2019 to March 2022 were chose as samples. All the subjects were distributed into 2 groups, namely A and B, and 55 people in each. B group were treated with secondary preventive drugs for CHD, and the A group were treated with nicorandil and secondary preventive drugs for CHD. After one month, the clinical efficacy, prethrombotic state, VEF, inflammatory factor levels, cardiac function were compared.</p> Results <p>The bg, DD, PAI-1, vWF, ET-1, TNF-α and hs-CRP in A group after the treatment were below those in B (<i>P</i> &lt; 0.05), t-PA, FMD, The NO content was significantly exceeded that of the B group. The LVEF and RHI indexes in A were exceed the data in B (<i>P</i> &lt; 0.05), and the LVEDD and LVPWd were below the data in B (<i>P</i> &lt; 0.05). The effective rate of clinical treatment in A was significantly exceed B’s data.</p> Conclusion <p>Nicorandil can significantly improve angina pectoris in elderly patients with DM and CHD.</p>