Novel pneumonia can be detected during the incubation period. Currently, the diagnosis of novel coronavirus relies on epidemiological contact history, signs and symptoms, chest imaging and routine blood test results. If the initial diagnosis of suspected infection has been made, the diagnosis can be confirmed by performing pathogenic testing on this basis. However, due to the low amount of latent virus, the detection rate may not be high, and the kits are expensive and scarce, so to avoid waste, patients need to be judged by the doctor to be a suspected infected person before further pathogenic testing can be done.