Mitral valve surgery has the most lesions, accounting for 75-95% of valve patients. Mitral valve replacement is the most commonly encountered surgical procedure, and with the continuous improvement of medical technology in China, the success rate of the procedure is now very high. The success rate is essentially 98% or more for large units and about 96% for medium units. The main factors that determine success are the patient’s underlying status and the patient’s cardiac function. Because most valve patients have a long medical history, many patients are afraid of the risk of surgery and are reluctant to do it early, and the risk is relatively high when the disease develops heavily. If the preoperative heart function is good, the success rate is relatively high; the patient’s preoperative heart function status is the most important factor affecting the success rate of surgery, and of course, it is also related to the experience of the hospital and the surgeon in charge. Although the success rate of mitral valve replacement surgery is high, surgery is risky and no surgery is 100% successful, so adequate preparation should be done before surgery to minimize the risk as much as possible.