Low rectal cancer or ultra-low rectal cancer (i.e., the lower end of the tumor is less than 5 cm from the anal opening) is the most ideal surgical procedure for rectal cancer to eradicate the tumor while preserving the anus. The specific practice is as follows: after the total mesenteric and total rectal resection, the rectum is cut off with a suture outside 3 cm from the lower end of the tumor with a curved cutting anastomosis, the sigmoid colon is cut off with a linear cutting anastomosis at a suitable position, and after the tumor is removed without contamination, the rectum is anastomosed with the intestinal wall at the proximal 10 cm from the sigmoid colon to the mesenteric margin. This method can achieve both low anus preservation, non-polluting surgery and pouch effect, and the patient can defecate normally within a short time after surgery. Patients can have normal bowel movements 10 days after surgery.