Influenza A (H 1N 1) is an infectious disease caused by influenza virus H 1N 1. The method of detecting influenza A in China South University of Science and Technology Hospital is generally a nucleic acid detection method based on PCR (polymerase chain reaction), that is, the virus nucleic acid is extracted from nasopharyngeal or oral secretions collected by patients, and gradually amplified in the PCR amplification process to detect whether the virus nucleic acid exists. This detection method has high sensitivity and specificity, can detect a very small amount of viruses, and can exclude some false positives or false negatives. In addition, this method is simple and fast, and can generally get results within a few hours, which has good practical application value for the detection of suspected swine flu patients.