The incidence of rectal cancer is increasing year by year, showing a trend of rejuvenation. Among them, the proportion of low rectal cancer is high, and due to its anatomical location and and the anatomical characteristics of partial peritoneal coverage or no coverage, it results in a high local recurrence rate, and most patients die due to the progression of local cancer, and the treatment of such patients is also extremely difficult. At present, the main means of treatment for patients with recurrence of rectal cancer after surgery and radiotherapy are surgery, radiotherapy, chemotherapy, Chinese medicine treatment and biological treatment, etc. Symptoms and signs of recurrence of rectal cancer: 1. Change of stool habit and blood in stool, etc.: Anal diagnosis is a common diagnostic method for recurrence of rectal cancer after surgery. Patients with recurrence of rectal cancer after surgery may have blood in stool or change in bowel habits, etc. 2.Urological symptoms: Patients with post-operative recurrence of rectal cancer may have corresponding urinary recurrence symptoms due to cancer cells invading ureter and bladder, etc. Pain: Pain is the most common initial symptom of postoperative recurrence of rectal cancer. Patients often have perineal drop, sacral pain and radiation to lower limbs when rectal cancer recurs. 4.Lumps: Patients with post-operative recurrence of rectal cancer can find nodular lumps under the skin of perineum, which are hard in texture and can appear as pressure pain. Only in the early stage of recurrence is it possible to operate again and be cured. Therefore, patients with rectal cancer should be repeatedly explained that they should be followed up regularly after surgery, especially in the first 2 or 3 years after surgery, and should be reexamined every 3 months. The review includes physical examination, colonoscopy or barium enema, and blood sampling for CEA and CA19-9. Persistent elevation of CEA and/or CA19-9 in asymptomatic patients indicates local recurrence or distant metastasis, especially liver metastasis, and further CT scan, MRI scan or PET-CT examination should be performed. Despite the above diagnostic methods, pathological diagnosis is still very important? If a mass is palpated, fine needle aspiration cytology can be performed under the guidance of finger examination. If the mass is not palpated by finger examination, the pathology can be retrieved by ultrasound. However, because ultrasound is greatly disturbed by intestinal gas, it is difficult to diagnose postoperative recurrence of rectal cancer by ultrasound-guided aspiration biopsy. Compared with ultrasound, CT is more sensitive to pelvic lesions, easier to determine the location of tumor and its relationship with surrounding tissues, and can easily measure the size of cancer foci and the distance from sacrococcygeal bone, which can accurately guide puncture biopsy? Treatment: The treatment of local recurrence of rectal cancer has always been a difficult problem. Many patients are difficult to remove the tumor completely when they visit the clinic, and radiotherapy alone can only reduce the symptoms but not improve the patient’s survival, so the treatment of local recurrence of rectal cancer must be comprehensive. According to the specific assessment of patients and lesions, for resectable or potentially resectable patients, surgery should be pursued and used in combination with preoperative radiotherapy, intraoperative radiotherapy, adjuvant radiotherapy and Chinese medicine; for unresectable patients, integrated treatment with combination of radiotherapy, chemotherapy, Chinese medicine and biological therapy should be recommended. The degree of surgical radicalization is the key to patient survival and local control. Preoperative radiotherapy aims to reduce the tumor volume to improve the resectability rate of surgery; intraoperative radiotherapy mainly targets the cancer cells that may remain at the surgical incision margin. For patients who cannot be resected radically, a combination of radiotherapy and chemotherapy should be chosen according to the patient’s physical condition, and if only chemotherapy is suitable, the principle of drug therapy for advanced rectal cancer should be adopted. Patients with potentially resectable transformation should be re-evaluated every 2 months and surgical resection should be performed if they become resectable. Concurrent radiotherapy is recommended if the patient can tolerate radiotherapy.