Transanal endoscopic microsurgery (TEM) is a minimally invasive anus-preserving technique for local excision of rectal tumors by endoscopy via the anal route, which can eliminate the need for transabdominal surgery for some low and middle-grade early rectal cancers. (1) TEM has the characteristics of endoscopy, laparoscopy and microsurgery, with good field exposure, accurate and complete resection, and can obtain high quality specimens for accurate pathological staging. (2) TEM avoids complications caused by major surgery and abdominal wounds, and is painless after surgery, with no restriction on activities and fast recovery. The operation time, bleeding, postoperative analgesia, and average hospital stay are significantly less than that of transabdominal surgery. 2.TEM indications: low to medium level non-tip broad-based benign rectal adenoma, early rectal cancer, rectal neuroendocrine tumor, mesenchymal tumor, rectal anastomotic stenosis and even rectovaginal fistula.