Coronavirus Disease 2019（COVID⁃19）is caused by the new coronavirus SARS⁃CoV⁃2 and is characterized by an exaggerated inflammatory response. SARS ⁃CoV ⁃2 can trigger coagulopathy and thrombosis in patients with covid ⁃ 19. In severe cases，50% of the patients had coagulopathy. Up to 40% of patients still have deep vein thrombosis（DVT）and pulmonary embolism（PTE）. Low molecular weight heparin（LMWH）is recom⁃ mended as prophylactic anticoagulant therapy，Besides the Anticoagulant effect of LMWH，nonanticoagulant prop⁃ erties such as the reduction in interleukin 6 release and increasing the number of Limba cells，it can delay or block the inflammatory“cytokine storm”