Abstract: Objective To assess the cost-effectiveness of human immunodeficiency virus (HIV) prevention strategies under varying intervention packages, budgetarylevels, and allocation proportions in an area, thereby providing a reference for optimizing resource allocation in acquired immunodeficiency syndrome (AIDS ) prevention and control. Methods: Demographic, epidemiological, and clinical progression data of the target population in an area from 2018 to 2024 were collected, along with the input costs and intervention coverage of HIV-related projects. The Optima model was utilized to predict and analyze the allocation of resources under equivalent budgets and to evaluate the epidemiological impacts of different investment levels. Results: ① On the basis of adjusting total investment in HIV interventions, expanding the overall investment would reduce additional new HIV infections and HIV-related deaths. However, marginal saturation effects would be observed when the total investment increased to 1.75 times the baseline level. ② Regarding structural adjustments in investment, under scenarios of current total investment or 1.75 times the total investment, increasing the proportion allocated to MSM (men who have sex with men) intervention programs (both elevated to 93% ) demonstrated the most cost-effective allocation of resources. ③ Among sub-projects targeting the MSM population, condom promotion programs for MSM exhibited superior cost-effectiveness. Conclusion: Increasing investment in HIV/AIDS interventions, optimizing resource allocation structures, and enhancing targeted interventions for the MSM population can effectively improve the epidemiological impacts of HIV/AIDS prevention and control efforts.