D-dimer is elevated in diseases such as deep vein thrombosis, disseminated intravascular coagulation, myocardial infarction, severe hepatitis, and pulmonary embolism, and can also be used as an effective observation indicator for thrombolytic therapy. D-dimer can reflect the formation and dissolution state of thrombosis in human body, quantitative detection of D-dimer in human serum or whole blood, for auxiliary diagnosis and monitoring of thrombolytic therapy, to exclude venous thrombosis and disseminated intravascular coagulation.