Abstract Background: The role of interleukin family in colon cancer remained controversial. The purpose of this study was to investigate the association between interleukin family and colon cancer progression through bioinformatics methods and to validate such association in clinical patients. Methods: A total of 15 differentially expressed interleukins between the colon cancer tissue and normal colon tissue were evaluated from the Cancer Genome Atlas (TCGA) database with R software and only interleukin-7 (IL-7) was significantly associated with survival. The signaling pathway associated with IL-7 was then investigated using gene enrichment analysis. In addition, subsets of TNM were analyzed in detail and univariate and multivariate COX regression analysis were conducted. Finally, we performed western blotting, immunohistochemistry, cell proliferation and cell apoptosis analysis to examine the expression of IL-7 in patients with intestinal cancer. Results: The study demonstrated that IL-7 could inhibit the progression of colon cancer. In addition, IL-7 was found to be associated with overall survival (OS) and pathological stage. Further analysis of IL-7 expression with clinical data indicated that IL-7 was a key factor in inhibiting colon cancer progression. Conclusion: IL-7 was a key factor in inhibiting the progression of colon cancer and was closely related to overall survival.