How long does it take for HIV infection to be detected is usually related to the testing method, usually around 1-3 weeks. 1. HIV Antibody Test: Detecting HIV antibodies in the blood is the most commonly used method at present, and the window period is about 3 weeks after infection. 2. HIV antigen test: Use anti-HIV-1 core antigen P24 monoclonal antibody preparation reagent to detect P24 antigen in serum by ELISA, the window period is about 2 weeks after infection. 3. HIV nucleic acid test: Direct examination of HIV RNA can detect HIV infection before serologic changes are detected, with a window period of about 1 week after infection. If there is a suspected HIV infection of high-risk behavior, it is recommended to carry out the test as soon as possible, confirmed diagnosis and early treatment to avoid aggravation of the disease.