People infected with the omicron strain of the new coronavirus, the clinical manifestations are mostly mild, such as fever, dry cough, sore throat, etc., or there may be no obvious clinical manifestations, but there may also be severe and critical illnesses, which are manifested as respiratory distress and hypoxemia. 1. Mild infection: symptoms are mild, mainly manifested as low to moderate fever, dry cough, dry throat, sore throat, nasal congestion, runny nose and other symptoms of upper respiratory tract infection, but the pathogenicity test is positive. 2. Severe and critical illness: mostly seen in the combination of underlying diseases, there may be respiratory distress, hypoxemia, etc., and in severe cases, it may rapidly progress to acute respiratory distress syndrome, septic shock, metabolic acidosis, coagulation dysfunction, and multi-organ failure, or even death. Omicron belongs to one of the mutated strains of Neocoronavirus. Although the prognosis of most patients is good, it spreads very fast, and its overall global risk is assessed as “very high”, which may lead to a wide spread of the virus around the world, and therefore should be strictly prevented and controlled.