1. Adult aged >=18years old, 2. Patients infected with new coronavirus confirmed by PCR 3. In the state of no oxygen at rest, the patient's SPO2<=94% or the oxygenation index is less than 300mmHg.

1. Adult aged >=18years old, 2. Patients infected with new coronavirus confirmed by PCR 3. In the state of no oxygen at rest, the patient's SPO2<=94% or the oxygenation index is less than 300mmHg.