New coronavirus asymptomatic infected persons are infectious, and their infectiousness may be strong or weak, depending mainly on the ability of asymptomatic infected persons to excrete virus, with individual differences. New coronavirus asymptomatic infected person, only by the new coronavirus infection, but no fever, cough, sore throat and other clinical symptoms, but respiratory specimens of new coronavirus pathogenicity, or serum specific IgM antibody test is positive. If an asymptomatically infected person with novel coronavirus has a high capacity to excrete more virus, he or she is more contagious; on the contrary, if the amount of virus excreted is low, the contagiousness is relatively weak. Asymptomatically infected people do not develop disease and are not easily recognized because they look fine on the outside and are highly invisible, so they should be given more attention in prevention and control. When there is no way to actively recognize whether others are asymptomatically infected or not, routine precautions should be taken from the perspective of prevention of novel coronaviruses, wearing masks, washing hands frequently, not gathering, ventilating indoors frequently, and receiving the new coronavirus vaccine in a timely manner.