ObjectiveTo analyze the changes in CD4⁺T lymphocyte (CD4 cells) levels and influencing factors in patients with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) before and after highly active anti-retroviral therapy (HAART) in Xining City, Qinghai Province, so as to provide a scientific basis for formulating corresponding follow-up intervention strategies. MethodsFrom February to July, 2023, 468 HIV/AIDS patients who received HAART in Xining, Qinghai Province were selected using a convenient sampling method for a questionnaire survey. Venous blood was collected and CD4 cell levels were detected by flow cytometry. SPSS 22.0 was used for t-test, analysis of variance and χ²⁃test, and multiple linear regression analysis was used to explore the level of CD4 cells and its main influencing factors in HIV/AIDS population after HAART. ResultsUnivariate analysis showed significant differences in baseline CD4 cell levels among people of different ages, nationalities, residential types and annual income (P<0.05). There were statistically significant differences in the most recent CD4 cell levels among people of different nationalities, different marital statuses, with or without regular physical exercise, with or without hypertension, different baseline CD4 cell count, different years since HIV diagnosis, different years of HAART treatment, and different treatment programs (P<0.05). Multiple linear regression analysis showed that the baseline CD4 cell count was 350‒499 (t=7.40) and ≥500 (t=6.69), the number of years of HAART treatment was 5‒9 (t=3.59) and ≥10 (t=4.54), the number of years of HIV diagnosis was ≥10 (t=-2.58), the number of people receiving second-line treatment (t=-2.49) and the latest CD4 cell levels after HAART were statistically correlated (P<0.05). ConclusionThe CD4 cell levels of HIV/AIDS population in Xining city of Qinghai Province are affected by many factors. Comprehensive health intervention should be carried out for this population, the implementation of early detection and treatment strategy should be strengthened, relevant physiological and biochemical indicators should be monitored regularly, and health education should be carried out, so as to encourage this population group to choose a healthy lifestyle, improving their quality of life from multiple dimensions.