Anticoagulant therapy refers to the application of anticoagulant drugs to treat or prevent the occurrence of blood clots that have already occurred. Anticoagulant drugs include heparin, both ordinary and low molecular heparin, which need to be injected subcutaneously and do not need to monitor coagulation index. Coumarins, including warfarin, are more effective in anticoagulation but require monitoring of coagulation parameters during application and may cause serious bleeding if overdosed. Newer anticoagulants such as dabigatran and rivaroxaban are now available in oral form and do not require monitoring of coagulation parameters during application. Anticoagulation is required for established thrombotic disorders, such as cerebral embolism and pulmonary embolism. For patients with persistent atrial fibrillation, hemodynamic instability and prone to thrombosis, prophylactic anticoagulation therapy is required. For people at high risk of thrombosis, such as erythrocytosis and antiphospholipid antibody syndrome, elderly people who are bedridden for a long time also need appropriate anticoagulation therapy to prevent the occurrence of thrombosis.