The antigen test and nucleic acid test referred to in the title should be the New Crown Antigen Test Kit and the New Crown Nucleic Acid Test, in which the antigen self-assessment has two bars but the nucleic acid test is negative, and the nucleic acid test is more accurate when comparing the two. Antigen self-test two bars have positive and false-positive situations, positive suggests that the body is infected by the virus, false-positive by the environment, operation and other factors, which can lead to bias in the results. Nucleic acid test is more sensitive, the accuracy rate can reach more than 95%, commonly used test methods are throat swab, nasal swab, anal swab. Comparison of the two ways of antigen self-test and nucleic acid test, antigen detection is less sensitive, so antigen self-test two bars, nucleic acid test is negative, nucleic acid test results should be the main. It is recommended to re-test several times to clarify the diagnosis and accurately determine whether the organism is infected by the virus. If there is fever, cough, etc., it is recommended to consult a doctor in time, combined with epidemiological history, lung imaging changes, blood routine and other comprehensive judgment, early treatment.