In recent years, with the improvement of people’s living standard, the incidence rate of colorectal cancer has also increased significantly due to the significant changes in the dietary structure and living habits of our people. Usually, we say colorectal cancer includes colon cancer, rectal cancer and anal canal cancer. The annual number of newborn patients of colorectal cancer in China is about 13-16 million, and the number of deaths is about 60-90 thousand. It ranks third after gastric cancer among gastrointestinal tumors. The age of incidence in China is mainly 40-50 years old, and youthfulness is the main feature of colorectal cancer in China. High-fat, high-protein and low-fiber foods, reduced exercise, environmental pollution and bad habits are all related to the development of colorectal cancer. Those who suffer from chronic inflammation of the intestine, polyps, adenomas and extensive ulcerative colitis for more than 10 years are the risk group of colorectal cancer, and obesity is also a concomitant form of high risk state of colon cancer, in addition, genetics may also play an important role in the factors of colorectal cancer development. The main symptoms include mucopurulent stools, change in bowel habits, alternating dry and dilute stools, abdominal pain and abdominal distension. The clinical manifestations are different depending on the location of the tumor. Right hemicolectasis is mainly systemic symptoms, including anemia, weakness, weight loss, abdominal mass and abdominal pain; while left hemicolectasis is mainly local symptoms, blood in stool is the most common symptom, followed by abdominal pain and abdominal distension. Left hemicolectomy cancer has a relatively short disease course and can show symptoms of intestinal obstruction. The main manifestation of rectal cancer is blood in stool and change of bowel habit. Bleeding and pain in the anus are the main clinical manifestations of anal canal cancer.