Transanal local excision of rectal tumors is mainly used for benign tumors, with less surgical trauma, faster recovery of intestinal function after surgery, and fewer complications. Traditional transanal surgery is difficult for resection of middle and upper rectal masses due to exposure restrictions, and is prone to recurrence due to positive margins or fragmentation of the specimen, with recurrence rates ranging from 4% to 57% as reported in the literature. TEM combines the advantages of endoscopy, laparoscopy and microsurgery, with good field exposure, the ability to remove tumors in the middle and upper rectum and even the sigmoid colon, precise resection, ideal specimens for pathological staging, and few complications. Professor Yin Lu of Ruijin Hospital has completed nearly 100 cases of TEM surgery with excellent postoperative results and a much lower recurrence rate compared to traditional transanal surgery. TEM is suitable for the treatment of large, non-tipped adenomas 4 to 18 cm from the anal verge, recurrent adenomas, low-risk rectal cancer (moderately differentiated to well-differentiated stage T1 lesions without lymphatic or neurological infiltration), fistulas and post-anastomotic rectal strictures. It is also an appropriate treatment for certain stage T2 and T3 rectal cancers with specific indications, such as palliative surgery for elderly or high-risk patients who are unwilling or unable to tolerate transabdominal radical surgery and local control for patients with extensive metastases.