Human infections with highly pathogenic avian influenza must be actively hospitalized if a clear diagnosis has been made, and patients with mild cases have a relatively good prognosis. If the infection is of the H5N1 subtype, severe cases may develop rapidly, often with complications such as severe pneumonia, respiratory distress, pulmonary hemorrhage, pleural effusion, multi-organ failure, sepsis, shock, etc. Therefore, if the case is severe, it must be hospitalized, and antiviral drugs should be actively used within 48 hours of the onset of the disease, the first choice being amantadine or oseltamivir. In the treatment of critically ill patients, the main points of treatment are to pay attention to nutritional support, and to strengthen blood oxygen monitoring and respiratory support, and to prevent and control secondary bacterial infections and other complications.