The incidence of colorectal cancer and diabetes is on the rise all over the world， and more and more patients with colorectal cancer are found to have diabetes at the same time in clinical practice. The most effective measure for colorectal cancer is radical surgery， but it increases the risk of surgery and the incidence of postoperative complications such as infection when applied to patients with colorectal cancer and diabetes. It has become a hot spot of clinical research to reduce the risk of surgery and the incidence of postoperative complications in patients with colorectal cancer and diabetes. In this article， we analyze the relationship between diabetes and colorectal cancer as well as the effect of colorectal cancer radical surgery on patients with colorectal cancer and diabetes; we review the current status of perioperative blood glucose management in patients with colorectal cancer and diabetes at home and abroad; we propose to strengthen perioperative blood glucose management of patients with colorectal cancer and diabetes to reduce the risk of surgery， prevent postoperative complications， and improve the quality of life of patients.