Abstract: The unique reverse transcriptase of human immunodeficiency virus-1 (HIV-1) has no proofreading function, making it one of the fastest-mutating viruses and evolving into numerous subtypes and subclusters during the global epidemic. Different HIV-1 strains have unique biological differences and changes in pathogenicity and are still evolving in transmission characteristics. This is very unfavorable for prevention and control departments to grasp complete information on the prevalence and pathogenicity of the virus, making it difficult to formulate targeted intervention work. In view of this, it is necessary to carry out comprehensive research on the pathogenic characteristics of virus strain subtypes, reveal the relationship between the adaptive evolution of the virus and the virulence level, clarify the impact of the genetic characteristics and heterogeneity of each subtype on the pathogenicity of the virus strain, and obtain complete data on HIV-1 genetic and phenotypic variations so as to improve the overall prevention and control effect of AIDS. This article focuses on summarizing the phenotypic characteristics of HIV-1 subtypes, virulence levels and the impact of immune reconstitution after antiviral therapy.