Mask oxygen inhalation and nasal catheter oxygen inhalation are common clinical methods. If the patient is severely hypoxic and needs a constant oxygen concentration, the best choice for oxygen inhalation after major surgery or coma patients is the mask, which can provide a constant inhaled oxygen concentration, can be humidified oxygen, less stimulation to the nasal mucosa, but will have a certain impact on eating and drinking water. The characteristics of oxygen inhalation through the nasal catheters are relatively simple, convenient, comfortable and cheap. It will not affect eating and drinking, but it may be affected by breathing and activities, and the oxygen concentration is not fixed.