From the outbreak of novel coronavirus pneumonia to the present, the criteria for judging critical illness have not changed, such as intravenous finger oxygen saturation ≤ 93% in the resting state; respiratory distress with respiratory rate ≥ 30 breaths/min; and arterial partial pressure of oxygen/oxygen concentration ≤ 300 mmHg, in accordance with either one. Taking a sample of more than 2,000 critically ill patients admitted, the critically ill patients are generally older and most of them have some underlying diseases, such as tumors, cardiovascular and cerebrovascular diseases, and pneumonia combined with dialysis patients. The current downward shift of seriously ill patients after reaching a peak of 989 on February 10 means that symptomatic treatment is becoming more effective, thus curbing the trend of mildly ill patients deteriorating into seriously ill patients.