DNA甲基化是发现的最早、最重要的表观遗传机制之一。 DNA甲基化一般是指在DNA甲基转移酶的催化下，以S-腺苷蛋氨酸为甲基供体，通过共价键合和化学修饰，在DNA序列的特定碱基上添加甲基。 DNA甲基化是诱发癌症的重要因素。 DNA甲基化有不同类型，不同位点的甲基化发挥不同的作用。众所周知，结直肠癌（CRC）的进展受到关键基因甲基化的影响。本综述不仅讨论了DNA甲基化与CRC之间的潜在关系，还讨论了DNA甲基化如何通过影响关键基因来影响CRC的发展。此外，还强调了DNA甲基化在结直肠癌中的临床意义，包括甲基化的治疗靶点和生物标志物；讨论了 DNA 甲基化抑制剂作为治疗 CRC 的新策略的重要性。本综述不仅关注最新的研究成果，还引用了早期的综述作为对旧文献的参考。

DNA methylation is one of the earliest and most significant epigenetic mechanisms discovered. DNA methylation refers, in general, to the addition of a methyl group to a specific base in the DNA sequence under the catalysis of DNA methyltransferase, with S‑adenosine methionine as the methyl donor, via covalent bonding and chemical modifications. DNA methylation is an important factor in inducing cancer. There are different types of DNA methylation, and methylation at different sites plays different roles. It is well known that the progression of colorectal cancer (CRC) is affected by the methylation of key genes. The present review did not only discuss the potential relationship between DNA methylation and CRC but also discussed how DNA methylation affects the development of CRC by affecting key genes. Furthermore, the clinical significance of DNA methylation in CRC was highlighted, including that of the therapeutic targets and biomarkers of methylation; and the importance of DNA methylation inhibitors was discussed as a novel strategy for treatment of CRC. The present review did not only focus upon the latest research findings, but earlier reviews were also cited as references to older literature.