The new crown nucleic acid test and the serum antibody test are known as dual tests. The Neo-Crown Nucleic Acid Test is evidence of infection by Neo-Crown virus; the Serum Antibody Test is primarily a test for serum IgM antibodies. If the nucleic acid test and the serum antibody test are both negative, it means that the patient is not infected by the new crown virus; if both tests are positive, it is a confirmed case; if the nucleic acid test is negative and the antibody test is positive, the patient may be in the infected or recovering stage, or may have received the new crown vaccine, which indicates that the antibody is present in the body. Nucleic acid test negative, IgM antibody test positive people need to do further examination, need to do nucleic acid test again, in order to rule out false negatives; patients should be aware of the precautionary approach, to avoid being infected by the new crown virus and then infected with others; if there are suspected symptoms of infection with the new crown pneumonia during the new crown pneumonia epidemic, you need to consult the doctor in a timely manner, complete the nucleic acid test. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article have been renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.