Influenza is mainly caused by influenza A or B virus infection. Patients mainly present with fever, headache and general malaise, with body temperature up to 39-40℃, accompanied by chills, malaise and loss of appetite. In the early stage, oseltamivir can be applied and the symptoms can improve in 3-4 days without complications. In contrast, patients with novel coronavirus pneumonia often develop fever, malaise, dry cough, a few with nasal congestion, diarrhea, etc. In severe cases, respiratory distress develops after 1 week, and in severe cases, it progresses to acute respiratory distress syndrome, septic shock, etc. The application of common antiviral drugs such as oseltamivir is not effective. The two are difficult to distinguish from clinical symptoms and need to be judged by combining epidemiological history, imaging and laboratory tests, and pathogenic findings.