Abstract: Colorectal cancer is one of the major diseases that threaten human health. With the development of microbiome technology in recent years, many studies have reported the relation between microorganisms and the pathogenesis and development of colorectal cancer, such as Fusobacterium nucleatum and Bacteroides fragilis were found to induce and promote colorectal cancer. In addition, some researchers discovered the inhibitory effect of some bacterial metabolites such as short-chain fatty acids on the occurrence and development of colorectal cancer. Based on the differential microorganisms between colorectal cancer patients and healthy controls, the diagnostic model could be established. In the field of colorectal cancer treatment, microorganisms may become drug targets for inhibiting the occurrence and development of colorectal cancer, and they could influence the efficacy and side effects of chemotherapeutic drugs. Combined with the recent research progress and the author's own research interest, this article will review the correlation of pathogenesis, early diagnosis and treatment of colorectal cancer with microorganisms.