Rectal high-grade intraepithelial neoplasia is clinically considered to be a kind of rectal precancerous lesion, the so-called precancerous lesion is the precursor of cancer, and rectal high-grade intraepithelial neoplasia can easily develop into rectal cancer. For high-grade intrarectal intraepithelial neoplasia, surgical treatment is recommended, and endoscopic resection of the lesion should be chosen according to the preoperative changes, and for highly suspected malignant lesions, resection of the diseased intestinal segments may be needed according to the specific conditions. After surgery, we should pay more attention to rest, eat a light and mild diet, avoid cold and spicy food, eat more vegetables and fruits, keep the bowel smooth, avoid constipation and have regular follow-up colonoscopy to observe whether there is any recurrence.