Prosthetic valves are currently divided into three main categories, one being mechanical valves and the other being biological valves. The two types of artificial valves have their own characteristics, advantages, and disadvantages. 1, mechanical flap (metal flap): by the senior alloy stainless steel or other materials for the flap frame, mounted on the flap of each identical pyrolytic carbon activity. It has the characteristics of acid resistance, alkali resistance, high temperature resistance, more wear-resistant for its characteristics. There are many models of this type of flap at home and abroad, but the basic function is the same, practice has proved that the flap work 80 years without significant wear, 110 years to see light wear marks. Mechanical flaps, made of titanium alloy and pyrolytic carbon, are divided into single-lobe and double-lobe flaps, which have the advantage of being durable, with a life expectancy of 40-50 years, and do not cause rejection of the body or calcification. These two types of flaps are now commonly used in clinical practice, with the bilobed flap being the most common, the disadvantage of which is that there is a possibility of valve failure and stuck flaps, with a chance of about 1%; lifelong anticoagulation is required, and anticoagulation accidents occur in about 1% of patients each year, resulting in embolism or bleeding of the body, which can cause serious complications or death, and a large amount of follow-up data confirm that the survival rate of mechanical flap replacement 20 years after surgery is only about 50%, with the main cause of death being complications of anticoagulation therapy The main cause of death is the complications of anticoagulation therapy, such as cerebral hemorrhage and cerebral embolism; 2, biological flap: a flap frame made of alloy stainless sodium or high-grade plastic, with a complex chemically treated biological tissue membrane (such as bovine pericardium, human or civet aortic valve, etc.) sewn between them as the flap. It is flexible, opens and closes flexibly, and approximates the working condition of the natural valves in the heart. Its major advantage is that it does not require lifelong anticoagulation, but only short-term anticoagulation, but its main disadvantage is that it is not as durable as mechanical valves, and some of the biologic valves can degenerate, decay, or perforate over several years of operation, thus requiring another valve replacement. Biological flaps, which are made from treated materials such as pericardium from pigs, cows, and other animals. Its advantages are that biological tissue is not easy to induce thrombosis, postoperative anticoagulation for three months can be, suitable for the elderly, remote rural patients, its disadvantage is the short life span, about 15 years, can occur calcification, tearing and loss of function, but the quality of survival of patients is good, now the clinical use of significantly increased, in the United States, the proportion of biological flap application has reached 80%, the proportion of domestic application of biological flap in recent years is also significantly higher, I applied In the United States, the proportion of biologic flaps has reached 80%, and in recent years, the proportion of biologic flaps used in China has also increased significantly. The advantages of the homogeneous valve, i.e., the isolated and preserved human aortic valve, are that it does not require postoperative anticoagulation therapy, it does not jam the valve, and it has a large opening area. It is suitable for adolescent patients, for those with small aortic annulus, and for the replacement of pulmonary and mitral valves and the treatment of complex precordial disease, with the disadvantage that it can cause rejection of the body, calcification and loss of function, with a life expectancy of about 10 years. Another type of tissue valve is the autologous pulmonary valve, which can be used to replace diseased aortic, mitral, and tricuspid valves. The type of prosthetic valve used must be determined by the physician based on the condition, age, general condition, and medical condition.