After a history of high-risk exposure to HIV, HIV test strips are generally recommended to be tested three times. The risk of HIV transmission is relatively high. If there is a history of high-risk exposure to HIV, the first and most important thing for the patient to do is to take blocking medications such as tenofovir, lamivudine, efavirenz, etc., as prescribed by the doctor, and the second thing is to test for HIV on a regular basis. Generally, it is recommended to take a test once every 2, 4 and 6 weeks, and if necessary, another test can be taken 3 months after the high-risk exposure. AIDS has a certain window period. With improved testing technology, the window period for most HIV tests is now generally 2-6 weeks, so it is recommended to be able to take the appropriate tests on a regular basis to rule out HIV. As testing technology improves, the window period will be shorter. If there is a history of high-risk exposure to HIV, counseling at a specialized HIV clinic, prompt administration of blocking medications, and active testing are recommended.