1.Introduction In the human body, there are valves in the heart and large blood vessels, whose role is to ensure the unidirectional flow of blood, that is, arterial blood centrifugal direction, venous blood is flowing in the direction of the heart, if the valve is damaged, it will make such a blood flow disorder, resulting in human morbidity. The ideal valve is one that is compatible with the body, does not fail mechanically, does not produce thrombosis, etc. The mechanical and biological valves currently used in clinical practice have certain drawbacks: the former require lifelong anticoagulation, are noisy, and may suffer from mechanical failure; the latter have a limited service life. 2, heart valve replacement indications mitral stenosis: if the valve leaflet activity is good, only the junctional adhesions or mild subvalvular damage, can strive to perform closed dilatation or direct vision shaping. If the valve is calcified or has funnel-like changes, valve replacement surgery is indicated. Mitral valve closure insufficiency: Direct visual angioplasty may be pursued in cases of enlarged mitral annulus or junctionally confined leaflet coiling. In cases of leaflet perforation and tendon rupture, mitral valve replacement surgery is indicated if it is difficult to completely correct the problem or if the procedure fails. Most mitral stenosis combined with mitral valve insufficiency requires valve replacement. Tricuspid valve damage: Usually, tricuspid valve replacement is not performed. Valve replacement surgery is performed only if the lesion is severe. Aortic stenosis: congenital aortic stenosis can often be performed during adolescence with direct visualization, while middle-aged and elderly aortic stenosis is mostly due to calcification on the basis of congenital aortic valvular bivalve malformation. Heart valve replacement – aortic valve replacement surgery – needs to be performed. Aortic valve insufficiency: Aortic valve insufficiency can be caused by valve annulus enlargement, leaflet tear perforation, coiling or prolapse, etc. Heart valve replacement should usually be performed. Only mild prolapse of the aortic valve may be subjected to valvuloplasty. Pulmonary valve lesions: Most are congenital malformations that rarely require valve replacement and often require right ventricle-pulmonary artery diversion with a valved conduit. Patients can compare the above common heart valve replacement indications to their own situation to decide whether they need heart valve replacement. Preoperative care is the same as the preoperative care for direct cardiac surgery with extracorporeal circulation, and anticoagulation knowledge and its importance are explained to patients and their families. Postoperative care: The same as postoperative care after direct cardiac surgery with extracorporeal circulation; special attention to the prevention of early postoperative arrhythmias; postoperative care of infection: correct and reasonable use of antibiotics. Anticoagulation care Prothrombin time is measured in the morning of the 3d postoperative day and is required to maintain prothrombin time at 1.5-2 times the normal value. Patients with replacement mechanical valves must take anticoagulants for life, and the following points should be noted: (1) The nurse should record the daily prothrombin time and oral warfarin dose during hospitalization, and let the patient bring his own record book to help find out the medication rule, and let the patient try to self-take so that he can develop the habit and record for life. (2) The oral warfarin should be controlled regularly and quantitatively, and the dosage should be accurate. (3) Pay attention to the signs of anticoagulation overdose: such as hematuria, rhinorrhea, subcutaneous blood, gum bleeding, occult blood in the stool, etc. If the above symptoms occur, the dose should generally be reduced or discontinued for 1 d. (4) Observe whether there is thrombosis, pay attention to the patient’s consciousness, limb activity, and contact the physician in time to adjust the dose of anticoagulant drugs if abnormalities are found. Health guidance 1.Take warfarin anticoagulant drugs on time and in quantity. 2.Regular follow-up come to the hospital outpatient clinic once every 2 weeks after discharge, and once every 4 weeks after 3 months; if the prothrombin time is unstable, the prothrombin time should still be measured 1-2 times a week. 3.Rest Six months after discharge, avoid excessive activity and exertion. But can gradually increase the amount of activity. 4.Take care of nutrition in diet. 5.Take cardiotonic and diuretic drugs as prescribed by the doctor. Avoid taking drugs that affect prothrombin time.