Painful symptoms will appear in the late stage of rectal cancer, mainly due to abdominal distension and abdominal pain caused by obstruction caused by tumor blocking intestinal cavity or painful symptoms caused by tumor compression and invasion of nerves. At the same time, the metabolites of cancer cells and necrotic tissues stimulate the human body and cause painful reactions. While patients have physical pain, they also have symptoms such as anxiety, irritability and depression, and the latter will further aggravate the pain to form a vicious circle, which seriously reduces the survival quality of patients. It is recommended that symptomatic treatment of pain symptoms should follow the three-step pain relief method for cancer recommended by the World Health Organization. The first step is mild pain, for non-opioid and non-steroidal anti-inflammatory drugs plus or minus adjuvant painkillers. Commonly used drugs include aspirin, ibuprofen, indomethacin, etc. Second order moderate pain, weak opioids plus or minus NSAIDs and adjuvant analgesics, commonly used drugs include codeine, prednisolone, tramadol, etc. Third order severe pain, opioids plus or minus NSAIDs and adjuvant analgesics are given, commonly used drugs are morphine. For pain management, active preventive medication should be taken, pain medication should be given regularly and on time, rather than when necessary, and the next medication should be given before the effect of the previous medication wears off can sustain analgesia.