Usually, once HIV exposure is established, the use of blocking drugs within 72 hours is effective, and the earlier blocking therapy is initiated, the more effective it is. Commonly used regimens include tenofovir, lamivudine in combination with efavirenz, or lopinavir in combination with ritonavir for antiviral blockade therapy. For patients who cannot tolerate these drugs, a combination of dolutegravir, abacavir, and lamivudine may also be considered. However, some patients may be allergic to abacavir due to individual differences. Therefore, it is necessary to closely monitor the occurrence of rashes and other allergic manifestations during the course of taking the drug, and to stop the drug immediately and go to the hospital in case of allergy. Usually, the course of blockade treatment is 28 days. Before and after the use of blockade drugs, including the 3rd month, HIV primary screening is required, and if the primary screening is still negative by the 3rd month, the possibility of infection can be ruled out.