HIV viral load of 0 is infectious, only the probability of infection is relatively low. HIV viral load of 0 when the AIDS patients tested, indicating that the patient’s body viral load is low, can not be detected by the instrument or due to the reasons of the detection method can not detect the HIV virus, and the human body infected with hiv after the virus is lifelong carriers, the HIV virus can not be completely disappeared, HIV viral load of 0 does not mean that the patient’s body does not have the HIV virus. Secondly, the test specimen for HIV viral load is blood, and a low viral load in blood does not mean that the viral load in semen, lymph fluid, cerebrospinal fluid, etc. is low. Therefore, an HIV viral carrier of 0 still carries the risk of transmission. HIV is transmitted through blood, sexual contact, and mother-to-child transmission, primarily through sexual intercourse. High-risk sexual activity with a patient who has a zero HIV viral load or the use of substandard blood products still poses a risk of transmission, and should be followed by timely hospitalization and, if necessary, interruption measures.