Antigen self-testing refers to the detection of new coronavirus antigens. Generally, two bars indicate a positive test, which does not confirm the diagnosis, but requires nucleic acid and antibody tests, as well as epidemiologic investigations. There are three levels of interpretation of antigen self-test results: if only the C line is colored, the result is negative; if both the C and T lines are colored, the result is positive; if only the T line is colored or colorless, the result is invalid. Therefore, when both the “C” and “T” lines show red or purple bands, regardless of the color, the result is positive. The diagnosis of neocoronavirus in clinical practice has strict epidemiologic and laboratory requirements, and can only be made if the patient has pathogenic or serologic evidence, such as a positive nucleic acid test for neocoronavirus, or a positive neocoronavirus-specific IgM antibody and IgG antibody without neocoronavirus vaccination. Therefore, when two bars in the neocoronavirus antigen self-test does not mean the diagnosis is confirmed, there are some false positives in the results of the antigen self-test, which need to be reconfirmed epidemiologically and serologically, and pathogenetically.