The accuracy of HIV antibody testing changes gradually as time progresses after a history of high-risk exposure, from 22% in the first week to 99% in the sixth week. According to official data released by the National Center for Disease Control and Prevention (NCDC), the detection rates of the third-generation HIV antibody test kits (colloidal gold method) used by most city and county CDC centers and hospitals are 22.6% in the first week, 53.7% in the second week, 84.1% in the third week, 98.4% in the fourth week, 99.45% in the fifth week, 99.994% in the sixth week, and close to 100 percent correctly detected in the eighth week. After a history of high-risk exposure, the HIV virus enters the human body, and the human immune system produces antibodies against the HIV virus, but there are differences in the speed and time of antibody production, and the window period for HIV antibody test reagents ranges from 3 weeks to 3 months. At week 4 after a history of high-risk exposure, the accuracy of HIV antibody detection is very high, and it is possible to make a preliminary judgment of whether or not one is infected with the HIV virus, but it is still not clear whether or not the final results, so it is recommended that the patient take the test several times at week 6, week 8, and week 12 after a history of high-risk exposure.