Thrombin is derived from bovine plasma and is composed of two peptide chains (31KD and 6KD) with disulfide bonds. Thrombin is A proteolytic enzyme formed after the activation of prothrombin, which catalyzes the hydrolysis of fibrinogen to A peptide and B peptide, thus forming fibrin monomer, which further polymerizes and forms blood clots with the participation of platelets, red blood cells and white blood cells.