Imported novel coronavirus infection is defined as a case in a region where there was no original case of infection, but the cases found in the region were transferred from abroad. The cases of 2019 novel coronavirus currently prevalent in China are imported cases or new cases caused by imported case infections in various provinces, cities, regions and abroad, in addition to the places where the outbreak originated. Imported cases are themselves infectious and may lead to infection in the surrounding population during the flow. The novel coronavirus is also highly contagious and has been shown to have human-to-human transmission, mainly through respiratory droplets, but also through contact, so the public needs to be protected.