【】Objective By constructing an immune-tumor dual humanized mouse model, explore the role of targeting monoamine oxidase A (MAOA) in the immune microenvironment of prostate cancer. Methods Utilize bioinformatics analysis to examine the relationship between MAOAhigh cancer-associated fibroblasts (CAFs) and T cells in prostate cancer; employ multiplex immunofluorescence to analyze the relationship between stromal MAOA and CD8+ T cells; construct an immune-tumor dual humanized mouse model to in vivo verify the infiltration of CD8+ T cells after targeting stromal MAOA. Results The expression of MAOA in the stroma is inversely proportional to the infiltration of CD8+ T cells; inhibiting MAOA in the stroma can enhance the infiltration of CD8+ T cells in vivo, which may be achieved by suppressing the accumulation of collagen in the tumor microenvironment. Conclusion Stromal MAOA plays an important role in the immunosuppressive microenvironment of prostate cancer, and inhibiting stromal MAOA can promote the infiltration of immune cells. MAOA inhibitors may serve as potential therapeutic drugs for immune combination therapy in patients with prostate cancer