Abstract： Objective　To understand the new HIV-1 infection in MSM (men who have sex with men) sentinel population in Haikou and explore the influencing factors of HIV/AIDS epidemic, so as to provide a basis for AIDS prevention and control. Methods　A continuous cross-sectional study was used to detect HIV-1 infection in the MSM sentinel surveillance population in Haikou City from 2019 to 2023, excluding those with known past positive results and those who had been on antiretroviral therapy for more than six months. The positive cases suitable for new infection testing were examined by HIV-1 restriction antigen affinity enzyme immunization method, and binary non-conditional logistic regression model conducted multivariate analysis of new infections. Results　A total of 2 001 MSM were recruited, with a median age M（P25, P75）of 28 (23, 33) years, 89.8% were recruited from the Internet, 90.8% were single; 79.7% resided in the local area for >2 years, 72.6% were educated to college level or above, and the proportion of household registration in the province was 78.0%. From 2019 to 2023, the HIV-1 positive rate among MSM in Haikou from 2019 to 2023 was 6.85% (137/2 001), with a new infection rate of 2.95% (59/2 001). The estimated new infection rate was 8.61% (95%CI: 6.41-10.81), with no significant trend changes in HIV-1 positivity and new infection rates over the years (P>0.05). Multivariate analysis revealed that, compared to those who lived locally for ≤2 years, those residing locally for >2 years had a lower probability of recent HIV-1 infection (OR=0.473，95%CI: 0.273-0.821). Compared to those who had never received intervention services, those who had received such services had a lower risk of recent HIV-1 infection (OR=0.347, 95%CI:0.197-0.613). Conclusions　In recent years, the Haikou MSM population has shown characteristics of higher education and younger age, and the rate of new HIV-1 infections has not changed significantly. Receiving intervention services is the protection factor to prevent HIV-1 new infections, whereas the mobile MSM population has a higher risk of HIV-1 new infection. Health management of the mobile MSM population should be strengthened to expand the coverage of AIDS intervention services.