Contact with a person with New Crown Pneumonia does not necessarily lead to infection; the chances of infection are related to the length of contact, the infectivity of the virus, whether or not protective measures are taken and the body’s immunity. Neocoronavirus pneumonia is short for novel coronavirus pneumonia, which is caused by 2019 coronavirus disease that infects the human body. Currently, its main sources of infection are patients and asymptomatic infected people, and it can be spread through respiratory transmission, direct or indirect contact transmission, and aerosols that may be present in confined environments. However, the realization of infection by novel coronaviruses is also limited by the following conditions: 1. Duration of contact: the longer the contact with the patient or asymptomatic infected person, the greater the chance of infection, whereas the possibility of infection by brushing against a person with good protective measures is very low. 2. Infection strength of virus particles: it is generally difficult to realize the infection in the case of weak infection ability of virus strains, and when the virus is strong, the chance of infection is greater. 3. Whether or not effective protective measures are taken in contact with the patient: if N95 masks and related protective measures are worn before contact with the patient, infection is generally not possible. 4. The immunity of the individual organism: for the elderly, children, low immunity of the population, it is more likely to be infected with the virus, while the immunity is relatively higher than the patient’s chances of infection after a brief contact is relatively small. During the new crown epidemic, go out to do a good job of personal protective measures to reduce the chances of infection. [Tip] This article refers to “new coronavirus pneumonia, new coronavirus pneumonia”, etc., has been December 26, 2022, the National Health Commission issued a notice to change the name to “new coronavirus infection”.