Chinese guidelines for diagnosis and treatment of HIV/AIDS(2021 edition), released in late 2021, are updated based on the previous four editions, according to the clinical practice in China and research data in the Chinese population, as well as the latest international research results. In the new guidelines, HIV resistance testing before the start of antiretroviral therapy(ART) is recommended; the importance of HIV load in HIV infection diagnosis, ART initiation and follow-up is emphasized; the progress in diagnostic technology for HIV-associated opportunistic infections(OIs), ART timing and regimens for patients with OIs, and secondary prevention for OIs is updated; the concept of rapid initiation of ART is advocated; the value and advantages of integrase inhibitors and coformulated single-tablet regimens are highlighted; the two-drug regimen containing dolutegravir/lamivudine is recommended for the first time, which shows that the antiviral drugs developed in China are recommended as the alternative ART regimens; the implementation and follow-up of pre-exposure prophylaxis (PrEP) is standardized for the first time; The five links and implementation processes of HIV whole process management are refined, which reflects the connection between HIV services and other chronic disease services and management. The updated guidelines reflect the progress of clinical and basic research on AIDS in China.