After engaging in high-risk behaviors, you need to go to the local HIV exposure sentinel hospital for antiretroviral drug blockade. After high-risk behaviors, such as sharing syringes and needles, unsafe sex, or importing unknown blood products, you should go to your local CDC or infectious disease hospital as soon as possible to buy antiviral medication for blockade within 24 hours; the shorter the time, the higher the success rate of the blockade; 24 hours is the golden period, with the effect of the blockade close to 100%, and the latest is no later than 72 hours. The course of medication is 28 consecutive days. After the occurrence of high-risk behavior exposure, antiviral drugs can block HIV from entering human cells, there are five major categories, more than 30 kinds of antiretroviral drugs can be used to treat HIV infection, commonly used AIDS blocking drugs are tenofovir, lamivudine, emtricitabine, ritonavir and so on. Drugs should be taken in combination under the guidance of a doctor.