Coronary angiography shows that the degree of stenosis is 70% or more, accompanied by severe angina or myocardial infarction, etc. If the effect of drug treatment is not good, you need to receive stent treatment. After decades of development, coronary intervention has become a very mature technology and is a very good treatment for coronary heart disease. The stents currently used in clinical practice are all very biocompatible and generally do not cause adverse reactions when placed in the human body. Coronary arteries have many branches like a tree, and many patients, especially those with combined diabetes, often have multiple vascular lesions or multiple lesions on one vessel. Interventional treatment is to place stents in important vascular lesions to achieve partial hemodynamic reconstruction. Simply put, a stent, like a small umbrella, is inserted through a sheath from the radial artery in the wrist or the femoral artery in the thigh, through which a catheter is inserted and, under X-ray guidance, moved to the stenosis site to open the small umbrella in order to dilate the stenosis and allow blood flow to pass smoothly. A small stent, 2-4 mm in diameter, weighs less than one ten-thousandth of a gram.