Objective：To explore the expression of SLC11A1 in multiple colon cancer data sets and its relationship with the clinical prognosis，and its potential role in the tumor microenvironment（TME） in colon cancer. Methods：With the use of the tumor genome atlas（TCGA） and the gene expression omnibus（GEO），the expression of SLC11A1 and its relationship with the clinical prognosis of colon cancer were analyzed. At the same time，we used the algorithm of ESTIMATE and the single-sample gene-set enrichment analysis（ssGSEA） algorithm to explore the relationship between SLC11A1 and immune cell infiltration within the TME. Results：In the TCGA and GEO datasets，the expression of SLC11A1 increased in tumor tissues（P<0.001） compared with normal tissues. High SLC11A1 expression was an independent risk factor for the overall survival（OS） of colon cancer patients. In addition，SLC11A1 was strongly linked to the infiltration and aggregation of tumor associated macrophages（TAMs） and M2-type macrophages，and further analysis indicated that it was strongly correlated with increased CD8+ T cell inhibitors TGFB1 and CXCL12 and their receptors. Conclusion：In summary，the expression of SLC11A1 is associated with the function regulation of cells in TME，especially TAMs and other immune cells，and it might have potential as a prognostic biomarker of colon cancer.