The probability of contracting novel coronavirus infection is the same for infected and healthy people wearing masks or not, and wearing masks significantly reduces infection. In public, close contact with an infected person who is also not wearing a mask carries a high risk of infection. However, the risk of infection was significantly reduced when both people wore masks and maintained a social distance of 1 meter or more. The scientific wearing of masks is an effective measure to prevent respiratory infections, both to protect yourself and others. Replace the mask when it gets wet and dirty and loses its protective effect. Wearing masks is necessary to stop the spread of the new crown pneumonia outbreak and to reduce the chance of infection in the population. During the new crown epidemic, you should be well protected and choose medical surgical masks or N95 masks that can effectively prevent viral infections. Try not to go to crowded places, wear a good mask when you go out, and wash and disinfect your hands when you go home. If fever, cough, sore throat, fatigue and other symptoms, immediately to the nearest fever clinic. Tip: “New coronavirus pneumonia and new coronavirus pneumonia” mentioned in this article have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.