Aged 40-65 years Voluntarily participate in this clinical trial and sign off "informed consent form" Chest imaging confirm COVID-19 featured lesions in the lung The SARS-CoV-2 nucleic acid test was positive Diagnosed with severe pneumonia of COVID-19: respiratory distress, Respiratory rate (RR) ≥ 30 times/min; resting oxygen saturation of 90% or less; arterial pressure of oxygen/the fraction of inspired oxygen≤ 300 mmHg; pulmonary imaging of focus within 24-48 hours > 50% progression

Aged 40-65 years Voluntarily participate in this clinical trial and sign off "informed consent form" Chest imaging confirm COVID-19 featured lesions in the lung The SARS-CoV-2 nucleic acid test was positive Diagnosed with severe pneumonia of COVID-19: respiratory distress, Respiratory rate (RR) ≥ 30 times/min; resting oxygen saturation of 90% or less; arterial pressure of oxygen/the fraction of inspired oxygen≤ 300 mmHg; pulmonary imaging of focus within 24-48 hours > 50% progression