Cancer pain is the main cause of suffering for patients with advanced cancer. According to statistics, about 80% of advanced cancer patients suffer from severe pain, and at least 15 million people worldwide suffer from pain every day. Most cancer pain patients can get satisfactory pain relief through “three-step” medication (oral analgesic drugs), but some of them are unable to receive medication due to poor effect of medication, inability to eat, contraindication to medication, economic burden or inability to tolerate side effects of analgesic drugs. They are called “intractable cancer pain” or “refractory cancer pain”. Such patients need to undergo invasive treatment. 1.Peripheral nerve block and minimally invasive interventional radiofrequency treatment When cancer pain is relatively limited and the effect of analgesic drugs is not effective, using local anesthetic drugs to block peripheral nerves or using radiofrequency to destroy nerves can often achieve satisfactory results. It is mainly used for limb cancer pain with limited pain areas, such as head, face, extremities, superficial chest and abdomen. Commonly used nerve blocks include supraorbital nerve block, infraorbital nerve block, chin nerve block, greater occipital nerve block, suprascapular nerve block, intercostal nerve block, thoracic nerve block, etc. 2. Epidural nerve disruption Epidural nerve disruption is a method of disrupting spinal nerve conduction by injecting nerve-disrupting drugs into the epidural cavity to produce segmental analgesia. Compared with peripheral nerve disruption, epidural nerve disruption can block both somatic and autonomic nerves, and the blocking range is large and the effect is precise. Because the nerve destruction drugs do not directly contact the spinal cord and cauda equina, the possibility of bladder and rectal sphincter involvement is less than that of subarachnoid nerve destruction. Chemical destruction of the celiac plexus Ethanol destruction of the celiac plexus is an effective method for treating pain caused by abdominal tumors, especially pancreatic cancer pain, and 60%-85% of patients can be completely pain-free. Abdominal plexus disruption is effective in relieving epigastric pain and back involvement pain caused by intra-abdominal tumors, most commonly in pancreatic cancer, but also in tumor-based pain in the distal esophagus, stomach, liver, bile duct, small intestine, proximal colon, adrenal glands and kidney. For pain caused by malignant tumors in the abdominal cavity, if treatment by other methods is not effective, destruction of the abdominal plexus can be considered. 4.Spinal cord electrical stimulation (SCS) is a new technology developed in the past 20 years, which replaces the “pain” of the lesion with a comfortable “tingling sensation” and achieves the purpose of analgesia. It has the outstanding advantages of not damaging nerves, completely reversible treatment process and not affecting the motor function of limbs, which is called “green therapy” in invasive cancer pain treatment. In the United States, nearly 200,000 patients receive such treatment every year and have obtained satisfactory analgesic effects. 5.Subarachnoid drug infusion system (morphine pump) Morphine is the “gold standard” of cancer pain treatment. The dose of morphine applied in the subarachnoid space is only 1/300 of oral dose and 1/100 of intravenous dose, and the reduction of dose greatly reduces the side effects of morphine on the one hand, and increases the space for drug adjustment on the other hand, which is conducive to obtaining the ideal analgesic effect. The system is implanted through local anesthesia surgery, and a single infusion of morphine can support six months of medication, which is effective for pain in all parts of the body, and can adjust the drug administration scheme according to different pain periods of patients, which is the most advanced method for the treatment of intractable cancer pain at present.