Carcinoma of the large intestine refers to malignant tumors originating in the large intestine, including colon and rectum cancer, and is a common malignant tumor of the digestive tract. The incidence rate of colorectal cancer has been increasing year by year, and it ranks second only to stomach cancer among gastrointestinal tumors. Foreign literature reports that the incidence rate of colorectal cancer ranges from 30 to 59 per 100,000 population, and the incidence rate of colorectal cancer in China is about 24 per 100,000 population. The age of onset is 40~60 years old, and the ratio of male to female is l~1.4:1. The site of onset is the rectum and sigmoid colon, among which rectal cancer accounts for about 50%. Treatment is still mainly based on surgery, and most scholars advocate comprehensive treatment.125I radioactive particle tumor bed residual cancer implantation, intra-tumor implantation and metastasis implantation are new technologies developed in recent years for the treatment of colorectal cancer, which provide another effective new treatment method for the comprehensive treatment of colorectal cancer, and make many patients who were thought to be incurable in the past see a new hope. The 2012 NCCN guidelines have clarified their importance.