Pelvic abdominal cancer is a kind of malignant tumor in digestive system, and in the late stage, due to cancer metastasis and nerve invasion, there will be more intense local pain. Pelvic cancer is a tumor that occurs in the junction of gallbladder, pancreas and duodenum, and patients with advanced stage have various symptoms, such as obstructive jaundice, nausea and vomiting, local metastasis and so on. Patients with advanced pot belly cancer often metastasize to lung tissue, liver tissue, or even invade nerves, so the cancer pain of patients with advanced pot belly cancer is relatively intense. For advanced cancer pain, “three-step” therapy is often adopted, i.e., the first step: non-opioid analgesics (such as aspirin, etc.) are used for patients with mild cancer pain; the second step: weak opioids (such as pethidine hydrochloride, etc.) are used for analgesics for patients with moderate cancer pain and those who are not effective in the first step; the third step: strong opioids (such as pethidine hydrochloride, etc.) are used for patients with severe cancer pain and those who are not effective in the second step; the third step: strong opioids are used for those who have serious cancer pain and those who are not effective in the second step. Strong opioids (e.g. morphine, etc.) are used for analgesia for those with poor effects. For those who need analgesia, drugs should be used under the guidance of doctors.