Inclusion Criteria:  Meets the diagnostic criteria for sepsis-3 developed by the American Society of Critical Care Medicine (SCCM)/European Critical Care Medicine Association (ESICM) Age ≥18 years old and age ≤80 years old. Procalcitonin ≥2 ng/ml  Exclusion Criteria:  Age<18 years, or age>80 years. Pregnancy or lactating A solid-organ or bone marrow transplant patients. Patients with myocardial infarction within the past 3 months. Advanced pulmonary fibrosis . Patients with cardiopulmonary resuscitation before enrollment. HIV-positive patients. granulocyte-deficient patients. blood/lymphatic system tumors are not remission. patients with limited care (lack of commitment to full aggressive life support). patients with long-term use of immunosuppressive drugs or with immunodeficiency. patients with advanced tumors. patients combined with non-infectious factors leading to the death(uncontrollable major bleeding, brain hernia, etc.). surgically unresolved infection sources(such as some intraperitoneal infection etc.) patients allergic to vitamin c. patients with G6PD deficiency.