The source of HIV infection is mainly people living with HIV. Now according to the epidemiological survey of AIDS: 1, the most important way of transmission is through extramarital sex, sexual promiscuity and infection by male homosexual sex. 2, through invasive operations in informal places, such as tattoos, intravenous drug use, etc. 3, through mother-to-child transmission, AIDS pregnant women without formal interruption may spread HIV to the next generation. In fact, HIV is very fragile and it is difficult to survive after leaving the body. The HIV virus is generally present in human blood, semen, female vaginal secretions, breast milk, other sweat, urine, saliva, tears, feces, basically do not contain the virus, so the daily life contact, is not infected.