A particularly shallow second bar of nucleic acid is usually indicative of a weakly positive self-test result for the new crown nucleic acid antigen. The second nucleic acid bar usually refers to the New Crown Pneumonia Antigen Self-Test kit, which allows the user to follow the instructions and interpret the results for themselves after sampling themselves. When the T and C positions both show clear bands, it suggests that the new coronavirus antigen test is positive. When the T and C positions have one dark and one light band, it suggests that it may be weakly positive, but it does not confirm the diagnosis, and it is often necessary to carry out the nucleic acid test again in order to help determine the accuracy of the results of the antigen self-test. Normally, the antigen self-test kit is only used as a preliminary screening, and the nucleic acid test results are still the main criterion. Residents should minimize visits to areas where people gather and follow local prevention and control policies. Tip: “New coronavirus pneumonia” and “new coronavirus pneumonia” mentioned in this article were renamed to “new coronavirus infection” on December 26, 2022, as announced by the National Health Commission.