Abstract: HIV/AIDS is a serious threat to public health and public health safety of infectious diseases. According to clinical symptoms, disease progression can be divided into acute phase, asymptomatic phase and AIDS phase three, HIV infected and AIDS patients two stages. HIV/AIDS diagnosis is based on epidemiological history, clinical symptoms, antigen/antibody and nucleic acid test results comprehensive analysis and judgment. When the antibody confirmation test result is uncertain, nucleic acid detection technology should be used in time to differentiate diagnosis, improve the detection rate of acute infection and the timeliness of diagnosis, seize the opportunity of early antiviral treatment, reduce the risk of social transmission and protect the immune function of HIV infected and AIDS patients.