AIM: To investigate of the effect of Shenqifuzheng injection (SFI) combined with PD-L1 antibody on tumor immune microenvironment and its efficacy. METHODS: A subcutaneous transplantation tumor model for B16F10-LUC melanoma was created. The expression of Ki67, CD31, CD8, CD16, CD163, FOXP3, LY6C, LY6G with labeling antibodies was used to detect CD8+T cells, Treg cells, NK cells, MDSCs cells, centrocytes, and granulocytes in the tumor tissues via immunohistochemistry. Flow cytometry was used to measure the ratios of CD11c+, IA/IE+, and CD80+ cells in splenic tissue, as well as the ratios of CD8+T, CD4+T, and Treg cells in tumor tissue. Additionally, granulocyte count and NK cell expression were analyzed. RESULTS: The immunohistochemistry results indicate that the drug administration group effectively suppressed tumor angiogenesis and cell proliferation, while decreasing the expression level of immunosuppressive cytokines CD4+T cells, Treg cells, MDSCs and centroblasts. Additionally, CD8 and NK cell infiltration was promoted compared to the control group. The results of the flow analysis demonstrated a significant increase in the expression level of CD8+T cells within tumor tissues, as well as inhibition of CD4+T, Treg, and DC cell infiltration within the spleen in the drug administration group. Additionally, the tumor volume analysis indicated that the drug administration group effectively inhibited tumor growth. The flow results illustrate that the group administering treatment exhibited significant increases in CD8+T cell expression levels in tumor tissue and DC cells in the spleen. Furthermore, the treatment effectively inhibited the infiltration of CD4+T and Treg cells. The results also indicate that the treatment significantly reduced tumor growth, with the tumor inhibition rate being better with PD-L1 antibody alone than with the SFI group. Additionally, combining drugs resulted in superior results compared to the PD-L1 antibody group alone. CONCLUSION: SFI combined with a PD-L1 antibody can have synergistic anti-tumor effects, potentially enhancing DC cell infiltration and promoting T cell activation. Immunohistochemistry results indicate a positive impact on the tumor immune microenvironment.