It has been nearly 200 years since rectal cancer was first reported in 1826, and nearly 100 years since the first transabdominal combined perineal surgery was performed in 1908 as the gold standard procedure for the radical treatment of rectal cancer. Only since the 1980s has there been a gradual shift to the current surgical treatment based on low or ultra-low anterior resection. The goal of radical surgery for rectal cancer has also changed from the initial “eradicating cancer and saving life” to “eradicating cancer and improving quality of life” and “curing cancer while taking into account the function of the anus”. The treatment of low rectal cancer in China has been changing from “eradicating the cancer and improving the quality of life” to “curing the cancer while taking care of the anal function”. Although there are still a lot of arguments in China about anal preservation surgery for low rectal cancer, such as the failure of anal preservation surgery to achieve curative effect and the high local recurrence rate after surgery, a lot of data have proved that there is no significant difference in the 5-year survival rate and local recurrence rate between transabdominal perineal colectomy and low anterior resection. Then, radical surgery should not violate the principle of radical surgery for the sake of anus preservation, but also not sacrifice the anus arbitrarily in the name of radical surgery, how to have the best of both worlds? This requires clinicians to strictly grasp the indications for surgery, while taking into account the principle of flexibility – the surgical margins and stripping surface must be free of cancer residue. Low anterior resection for low rectal cancer was first advocated in 1982 and is now accepted by most scholars. The indications are: 1) cancer of the middle and lower rectum, 2) tumors below stage T3, where the cancer does not invade the plasma membrane layer, and 3) most patients with rectal cancer suitable for low anterior resection. This procedure can achieve the following effects: 1) reduce the local recurrence rate, 2) improve the success rate of anus-preserving surgery, 3) improve the urinary reproductive function after surgery, and 4) improve the 5-year survival rate after surgery. The current research confirms that the lymphatic spread of rectal cancer is mainly upward, especially above the peritoneal fold, and rarely spreads laterally and inferiorly. Only highly malignant or advanced cancer will spread retrogradely downward after the upward lymphatic vessels are blocked by the cancer embolus, and most of the spread is less than 2.5 cm. 2. As long as the anal canal, anal sphincter and anal levator are preserved, the anus can be preserved and normal defecation function can be maintained. Triple anastomosis 5.Trans-pubic low rectal cancer resection 6.Trans-abdominal sacral colectomy 7.Local resection of rectal cancer Indications for local resection of rectal cancer: Local resection of rectal cancer should remove the whole tumor as well as the normal tissues at the edge of the tumor, and proper selection of patients is the key to successful surgery. The ideal selection should be: 1. the diameter of tumor should be less than 4cm; 2. the tumor occupies less than 40% of the circumference of intestinal canal; 3. the lymph nodes on the surface of rectal mesentery are not touched. The indications for anal preservation surgery for rectal cancer: 1. After the rectum is fully free, the lower edge of the cancer is not less than 6 cm from the dentate line, and after removing 3 cm of normal rectum distal to the tumor, if the anal raphe, anal sphincter and anal canal are not damaged, anal preservation surgery can be considered. If the residual rectum is 2-3 cm, double anastomosis can be considered; if the residual rectum is less than 1 cm, Parks surgery should be performed. 2.For low rectal cancer with extensive local infiltration, tissue typing is undifferentiated cancer or mucinous cancer and inguinal lymph nodes have metastasis, APR is still appropriate. 3.When the cancer is confined to the mucosa or submucosa layer, the diameter of the cancer is less than 3 cm, occupying less than 40% of the intestinal wall, and the tissue typing is less than 40%. 4.For female patients with low rectal cancer, especially when the cancer is located in the anterior rectal wall, anal preservation surgery should be used with caution, unless posterior pelvic debridement is performed at the same time.