The treatment of rectal cancer needs to be mainly surgical, supplemented by chemotherapy and radiotherapy. 1.Surgical treatment: 1.Radical surgery Combined transabdominal perineal resection (Miles surgery) is suitable for cancer of the lower rectum less than 7cm from the anal verge, and the resection area includes sigmoid colon and its lining, rectum, anal canal, anal raphe, skin around the anus, blood vessels are ligated and cut at the root of the inferior mesenteric artery or below the left colonic artery division, and the corresponding para-arterial lymph nodes are cleared. A permanent colostomy (artificial anus) is made in the abdomen. This procedure has a complete resection and high cure rate. However, many studies have found that the oncologic prognosis of transabdominal perineal resection for rectal cancer is significantly worse than that of anterior rectal resection. Positive circumferential margins and intraoperative bowel perforation are considered to be the main reasons for the poor prognosis after APR. In recent years, European surgeons have proposed a new surgical concept-extra-levator abdominoperineal excision (ELAPE). This procedure emphasizes freeing along the lateral plane of the levator abdominis muscle and removing the anal canal, levator abdominis muscle and low rectal mesentery as a whole, without excising too much of the colorectal fossa and perianal skin, which can effectively reduce the intraoperative perforation rate and positive CRM rate of the specimen without increasing perineal complications and significantly improve the prognosis. Therefore, ELAPE surgery is considered to be one of the major advances in surgical techniques in the 21st century. Transabdominal anterior rectal resection (Dixon procedure), which is applicable to upper rectal cancer more than 12 cm from the anal verge, is performed by intraperitoneal resection of the sigmoid colon and large part of the rectum, freeing the rectum below the peritoneal reflex, and extraperitoneal anastomosis of the sigmoid colon and the cut end of the rectum. This operation is less damaging and can preserve the original anus, which is more ideal. If the cancer is large and has infiltrated the surrounding tissues, it should not be used. This type of surgery follows the principle of complete rectal mesenteric excision (TME). However, for patients with obesity and pelvic stenosis, it is difficult to reveal the operative field, and transabdominal resection has the risk of tumor residue and difficulty in preserving the anus; therefore, in 2010, Lacy et al. in Spain proposed transanal TME surgery. It not only improves the quality of surgery and reduces the recurrence rate, but also increases the chance of preserving the anus. 2.Palliative surgery If the cancer has severe local infiltration or extensive metastasis and cannot be cured, in order to relieve the obstruction and reduce the patient’s pain, palliative resection is feasible by making a limited resection of the intestinal segment with cancer, sewing up the distal rectal cut and taking the sigmoid colon for stoma (Hartma surgery). If this is not possible, only sigmoidostomy will be performed, especially in patients with intestinal obstruction. Radiation therapy has an important position in the treatment of rectal cancer. At present, it is believed that the survival period of preoperative simultaneous radiotherapy followed by surgery is longer than that of surgery followed by radiotherapy for low and middle-grade rectal cancer with late local staging. III. Chemotherapy Patients with postoperative pathological stage II and III of rectal cancer are recommended to undergo postoperative chemotherapy with a total chemotherapy duration of six months.