In patients with novel coronavirus infection, the oxygen saturation is generally not significantly different than usual in the mild and common types, and is 98%-100% in normal individuals. Oxygen saturation may be reduced in people with preexisting lung dysfunction such as chronic obstructive pulmonary disease or pulmonary fibrosis. Heavy patients with novel coronavirus may develop respiratory distress with a respiratory rate of ≥30 breaths/min, hypoxemia when measuring oxygen saturation in a calm state with its ≤93%, arterial partial pressure of oxygen and degree of oxygen inhalation will be ≤300 mmHg, and patients with critical forms of novel coronavirus pneumonia will develop uncorrectable respiratory failure, progressive decrease in oxygen saturation, which requires tracheal intubation and Ventilator to maintain respiration.