Commonly used laboratory coagulation indicators include DD, PT, APTT, and Fg. DD is the product of fibrinolytic solubilization of fibrin, and the elevated level of DD indicates that there is a hypercoagulating state and secondary fibrinolysis in the body, which can be seen in increased fibrinolytic activity of the body system [12–15]. PT and APTT are exogenous and endogenous coagulating system factors, which can be used for early diagnosis of DIC. Fg is a protein with coagulation function synthesized by the liver, which is an important substance in the process of coagulation and thrombosis. High level of Fg is an important indicator for a variety of thrombotic diseases. DD, PT, APTT, and Fg can be used as sensitive indicators to reflect different degrees of coagulating dysfunction. Therefore, in this article, the study was focused on if these indicators are related to the severity of COVID-19.