In clinical practice, oxygen therapy is needed for various reasons, but there are many side effects if there is an overdose of oxygen, which may include chest pain, chest tightness, coughing, reflex nausea, vomiting, general convulsions, and even convulsions, coma, lethargy, and cause blindness of the eyes. As excessive oxygen inhalation will cause the body to produce a large number of oxygen free radicals, which will attack and kill the normal cells of the body at this time, causing the metabolic dysfunction of cells, tissues and organs, and even inducing the occurrence of cancer. Therefore, we should pay attention to the contraindications and indications of oxygen inhalation in clinical practice, closely grasp the corresponding time and concentration of oxygen inhalation, and avoid oxygen overdose. The principle of treatment is mainly to get out of the hyperoxic environment and to carry out symptomatic treatment, such as sedation, anticonvulsant and nutritional support treatment.