Anticoagulant therapy is the most commonly used treatment for the prevention and treatment of thrombotic diseases in clinical practice. Common anticoagulant drugs include: i. Anti-platelet antibacterial drugs, commonly aspirin, dipyridamole, clopidogrel, etc. These drugs have the function of anti-platelet aggregation and adhesion, which can prevent cerebral thrombosis, coronary heart disease, myocardial infarction and other diseases. Second, bicoumarins, the longest is warfarin, which can competitively inhibit the absorption of vitamin K and reduce the synthesis of coagulation factors related to vitamin K. Clinically, they are often used in the treatment of anticoagulation after heart valve surgery. Third, heparin anticoagulants, commonly used clinically for disseminated intravascular coagulation, as well as other drugs that require anticoagulation treatment. All anticoagulant drugs must be monitored for clotting time and partially activated prothrombin time when applied to prevent bleeding due to overdose of anticoagulant drugs.