Sexual contact with HIV patients is not necessarily contagious, but only has a certain chance of transmission. Whether HIV transmission occurs is influenced by a variety of factors. AIDS is a relatively common chronic infectious disease, the general transmission channels are mainly blood contact transmission, body fluid contact transmission, sexual contact transmission, etc., especially unclean sexual contact, easy to cause HIV infection. Whether HIV infection will be affected by a variety of factors, such as the amount of virus in the patient’s body, the process of sexual contact exposure, are factors that affect the transmission. In addition, sexual contact in individual cases, such as male homosexuality or male to female transmission, may have a higher chance. Therefore, in order to prevent the transmission of HIV, one should develop good living habits, avoid unclean sexual contact, and take formal preventive measures if necessary, which can prevent the transmission of HIV.