Because the New Coronavirus Nucleic Acid Test has a certain detection error or because it is difficult to detect the virus because of the low viral load during the recovery period, the New Coronavirus Nucleic Acid Test may return to positive after 16 days of conversion. The new coronavirus nucleic acid test may have a certain degree of error. Therefore, clinically there is a risk of false negatives with the new coronavirus nucleic acid test. Moreover, if the patient is recovering from the disease, the body’s detoxification will be reduced and the pharyngeal secretions will contain less virus. The epithelial cells carrying the virus may not be detected during sampling, which may also lead to a false-negative test result. Therefore, the new coronavirus nucleic acid test may also be positive again 16 days after the test has turned negative. The new coronavirus is a highly contagious virus, even after the new coronavirus nucleic acid test is negative, you still need to take good personal protective measures, and wear a mask when you go out.