Object: Immunotherapy targeting PD-1 and CTLA-4 have made breakthrough in cancer treatment. However, the Cases of Colorectal Cancer (CRC) with Microsatellite Stable (MSS) do not respond to the dual therapy. Thus, new strategy will be needed to overcome this limitation. A Traditional Chinese Medicine (TCM) Shengqi Yichang (SQYC) decoction has been proven to be effective in controlling CRC growth and enhancing patients’ immune cells number in clinic. Methods: Here, an orthotropic MSS CRC tumor model (CT26-Luc cells) was used to observe the anti-tumor effect of SQYC decoction. A serial of comprehensive studies, including systemic pharmacological screening, RNA-sequencing, Single cell sequencing, metabolomics, and proteomics analysis were performed to uncover the mechanisms of SQYC in enhancing the immune cells infiltration. Meanwhile, experimental validations were conducted to confirm the predicted results, such as qPCR for the hub genes expression, flow cytometry for T cell infiltration, ELISA assay for the concentrations of major metabolites. Results: Animal experiments indicated that SQYC decoction inhibited MSS CRC growth and increased the response of tumors to dual immune checkpoint inhibitors (ICIs). Pharmacological study revealed that SQYC contained 14 main components and 11 key genes (Trp53, PRKACB, AKT1, MAPK1, MAPK3, JUN, TNF, IL-6, IL-1?, CD44, MAPK8), to be involved in multiple pathways. Single cell RNA sequencing revealed that SQYC decoction acts as an anti-tumor immune promoter by increasing the proliferation and functions of CD8+ T effector cells in MSS CRC tumors. Based on metabolomics analyses, profoundly altered metabolites were identified, four metabolic pathways, namely linoleic acid, glycerophospholipid, choline and arachidonic acid metabolisms were explored. We found 99 down-regulated proteins and 190 up-regulated proteins in SQYC group by proteomics analysis. The enrichment gathered in anti-tumor immune therapy related signings, including PD-L1 expression and PD-1 checkpoint pathway, neutrophil extracellular trap formation, natural killer cell mediated cytotoxicity and IL-17 signaling pathway. Conclusion: SQYC decoction might act as a novel therapeutic strategy for CRC patients with MSS tumors.