A catheter is first inserted into the femoral artery at the base of the thigh or the flexor artery at the wrist, as in coronary angiography. After the catheter is delivered to the opening of the coronary artery, a guide wire is inserted through the catheter into the coronary artery through the stenosis outside of the body and a catheter with a balloon at the tip is delivered along the guide wire to the obstruction site. When the balloon reaches the position of expansion, the balloon will be pressurized to expand, so that the mechanical compression of atherosclerotic plaque on the arterial wall, so that the lumen of the blood vessel to expand, and then sent into the appropriate length and diameter of the stent to support up, so that the stenosis of the blood vessel to restore the normal blood flow, the patient’s angina pectoris will be relieved.