Prevention of infectious diseases, in addition to vaccination for prevention; mainly from three aspects: first, control the source of infection. Second, cut off the transmission route. Third, susceptible people. Control the source of infection, mainly refers to the infectious patients, to achieve early detection, early diagnosis, early isolation, to prevent the spread of infectious diseases. Cut off the route of infection, mainly refers to the need to pay attention to personal hygiene as well as environmental hygiene, to disinfect the particular route of infection. Protecting susceptible individuals, during an epidemic, care should be taken to protect patients who are susceptible to infection, such as elderly patients and those with low resistance. And if one’s resistance is low, one should try not to come into contact with people suspected to be infected and should pay attention to exercise to improve one’s immunity so as to be able to resist infectious diseases.