Inhibitors of thrombin, which have antithrombotic effects. Commonly used thrombin inhibitors include dabigatranate, bivalirudin, and argatroban.1. Dabigatranate: It is a new oral thrombin inhibitor, generally used in patients with atrial fibrillation. As a precursor drug, it must be metabolized before it becomes an active drug. The half-life of dabigatranate is 12-14 hours, therefore, 2 doses are needed in 1 day to ensure a continuous anticoagulant effect. Dabigatranate is mainly excreted through the kidneys, so it should be reduced when taken by people with renal insufficiency to avoid excessive accumulation of anticoagulants in the body secondary to bleeding; 2. Bivalirudin: It is a direct thrombin inhibitor applied intravenously. Its advantage is that the half-life is relatively short, 20-25min, but the disadvantage is also more significant, bivalirudin can only be administered intravenously, and easy to secondary bleeding. Therefore, it is important to monitor for bleeding during the administration of the drug. This drug is mainly used after PCI and therefore should not be used routinely in patients with atrial fibrillation. In addition, patients with renal impairment need to reduce the dosage. 3. Argatroban: It is relatively less used in clinical practice and is also a direct antithrombin inhibitor applied intravenously to improve symptoms such as ulceration of the extremities, resting pain and coldness in patients with chronic arterial occlusive disease. It is mainly metabolized by the liver, therefore, it needs to be applied in reduced dosage when the liver is not fully functional.