HIV nucleic acid testing is one of the most accurate tests. Nucleic acid testing is the use of PCR to detect the presence of the HIV virus in the patient’s blood. After an ordinary person is infected with HIV, the HIV virus will appear in the blood in about 5 days, and the presence of the virus can be detected in the infected person’s body through HIV-RNA testing in 7-10 days, thus confirming the diagnosis. Not only the nucleic acid test can confirm the diagnosis, but also the combination of HIV antigen and antibody test can be used to confirm the diagnosis, but the combination of antigen and antibody test can only be detected about 2-3 weeks after HIV infection. Regardless of the method, once HIV infection is confirmed, the patient should be treated with antiviral drugs as soon as possible to avoid progression to the AIDS stage.