Nucleic acid testing for NCCP is a laboratory method of detection and screening, which plays an important role in detecting confirmed cases of NCCP, suspected cases and asymptomatic infections, ensuring “early detection, early reporting, early isolation and early treatment”, and rapidly cutting off the transmission of the virus. In order to improve the standardization and timeliness of nucleic acid testing, the results of nucleic acid testing for outpatients with fever are generally available within 4-6 hours; the results of nucleic acid testing for general outpatients, inpatients and escorts are available within 12 hours; the results of nucleic acid testing for people who are willing to be tested are generally available within 24 hours. In addition, for difficult specimens, the need to repeat the test, or even the need to repeat the specimen collection, the time required will be appropriately extended. Novel coronavirus has a certain incubation period, usually one test result can not completely exclude whether the infection of new coronavirus, for people in low-risk areas, nucleic acid testing once is sufficient, but for close contacts, suspected cases of people, when the risk of disease is not removed, may need to repeat the test several times until the risk is removed. In case of suspected new coronavirus infection or asymptomatic infection, a combination of nucleic acid testing and antibody testing is also required. It is important to note that nucleic acid testing is generally valid for 3-7 days, and a negative nucleic acid test result does not mean that it is always negative, and can only temporarily exclude the possibility of infection with a new coronavirus, and there is still a risk of infection at a later stage. If a person who has tested negative is exposed to a confirmed or suspected case of novel coronavirus pneumonia or goes to a medium to high risk area, he or she will need to be retested again.