H7N9 avian influenza virus is a new subtype of influenza A virus, due to the high variability of influenza A virus, can be derived from many varieties, H7N9 is only one of them, mainly through the avian to human transmission, interpersonal basically will not be transmitted. Infected people generally show flu-like symptoms, such as fever, joint pain, headache, muscle aches and general discomfort, which can be cured after a week or so. In severe cases, the disease is progressively aggravated and manifests as severe pneumonia, with persistent high fever that does not subside, and respiratory distress, chest tightness, and hypoxia, which can rapidly progress to acute respiratory distress, respiratory failure, mediastinal emphysema, sepsis, shock, impaired consciousness, and multi-organ failure, with poor prognosis and high mortality. Therefore, during the epidemic period, once contacted with suspected sick and dead birds, if fever, joint pain, headache, chest tightness and other related symptoms appear, you should be alert to the possibility of avian influenza and should promptly go to the hospital for consultation.