When cancer develops into advanced stage, about 70% of patients have different degrees of cancer pain, and most of them cannot be treated satisfactorily. At present, WHO recommends that “three-step treatment” is the first choice for cancer pain. Clinical practice at home and abroad has proved that more than 90% of cancer pain patients can get pain relief and improve their quality of life if they are treated strictly according to the principle of “three-step therapy”. The principles of “three-step therapy” are: 1) oral administration of drugs; 2) administration of drugs on time; 3) administration of drugs according to the ladder; 4) individualization of drug dosage. The first ladder: non-steroidal anti-inflammatory and analgesic drugs (NSAIDS), the mechanism of action of NSAIDS is to inhibit the enzyme cyclo-oxygenase to reduce the synthesis of prostaglandins (PG), including PGE-1 and PGE-2. PGE-1 has the effect of maintaining the normal function of the kidneys, platelets, and protecting the mucous membrane of the gastrointestinal tract, while PGE-2 has the effect of inflammation and pain. Traditional NSAIDS on PGE-1 and PGE-2 synthesis inhibition is not selective, so in the play of analgesic effect at the same time, will inevitably appear gastrointestinal stimulation, renal damage and coagulation dysfunction and other side effects. The current development of NSAIDS new drugs, trying to selectively inhibit PGE-2, or by changing the chemical structure of the drug, or the use of controlled-release and sustained-release technology, in order to reduce the side effects of NSAIDS, can be selected from more than a dozen NSAIDS, WHO recommended representative of the drug for aspirin. Anti-inflammatory pain is more commonly used in the clinic, there are ordinary anti-inflammatory pain tablets, anti-inflammatory pain suppositories and anti-inflammatory pain controlled-release tablets (Ishidin) three kinds of dosage forms. The common dose is 25-50mg three times a day, taken orally with meals. For patients who cannot take it orally, anti-inflammatory pain suppositories can be used for rectal administration, which not only reduces gastrointestinal irritation, but also eliminates the first-pass effect. Through controlled release technology, the anti-inflammatory and analgesic effect can be maintained for 12h, thus avoiding the side effects caused by too high blood concentration. In addition, it can also be used as painkillers, Oxytetracycline and Euthyrox. The second stage: weak opioids are the main drugs used, and codeine is the representative drug recommended by WHO. Codeine is transformed into morphine in the body, which acts on morphine receptors and exerts analgesic effects, with an analgesic efficacy of 1/12 of that of morphine, a duration similar to that of morphine, a weaker sense of euphoria and addiction than that of morphine, and a slight inhibition of the respiratory center, with no obvious constipation, urinary retention, postural hypotension and other side effects. Lugaike is a compound preparation of dihydrocodeine 10mg and acetaminophen 500mg, which can exert analgesic effects through different pathways. The oral dose is 1 to 2 tablets/dose every 6h. Chimandine is an extended-release tablet of tramadol hydrochloride, which enhances analgesia by agonizing different receptors (opioid receptors and alpha receptors) in the center. Starting with 50mg orally, the dosage should be increased gradually, generally not more than 400mg/d, and the interval between doses should not be less than 8h. Shuangke is codeine controlled-release tablets, the analgesic effect is twice as much as that of codeine, and the interval between doses can be prolonged, without interfering with sleep, and it can be taken once every 12h, with 60-120mg each time, the above mentioned medicines can be chosen according to the patient’s degree of pain and drug-resistant situation. The third ladder: the medication is mainly strong opioids, and the representative drug recommended by WHO is morphine. Morphine acts on the central opioid receptors and has strong analgesic, sedative and cough suppressant effects. Because of the poor selectivity of opioid receptors, it can inhibit the respiratory center, narrow the pupil, dilate the resistance and volume vessels (causing postural hypotension), excite the intestinal smooth muscle and sphincter (causing constipation), contract the ureter and increase the tension of the bladder sphincter (causing urinary retention) and other side effects, and repeated application can lead to tolerance, addiction and other side effects. Oral morphine is available in two dosage forms. The immediate-release type has been abandoned because of its short duration of action, cumbersome administration, unstable blood concentration and easy addiction. Controlled-release type can make morphine release slowly, reduce the number of times of administration, maintain a more stable blood concentration, and fewer side effects. Mescaline (morphine hydrochloride controlled-release tablets) is commonly used in the clinic and is administered once every 12h. The third step of medication should especially follow the principle of on-time administration and individualized dosage, remove the traditional concept of morphine medication (fear of addiction, emphasis on respiratory depression), and should be mainly based on the patient’s degree of tolerance to completely relieve the pain of medication. The principle of “administering the drug on time” can maintain a stable blood concentration, which can effectively relieve pain and avoid the production of euphoria, and is not easy to become addicted, which must be clearly explained to the patients and their families. This point must be clearly explained to patients and their families. “Administering drugs when in pain” is a major taboo in cancer pain treatment. The clinical dosage of morphine is highly variable and is related to the existence of individual differences in sensitivity to opioid receptors, and clinical administration should follow the principle of dose individualization. The dose of methocarbamol can sometimes be as high as 1200mg/d; there are reports that methocarbamol 10mg/d can be maintained for months or even years. Therefore, morphine preparations should be used reasonably with proper assessment of the patient’s pain level to completely relieve the patient’s pain. A considerable portion of patients with advanced cancer pain are accompanied by severe generalized pain. Intense pain seriously affects the rest, sleep, emotion and diet of cancer patients, greatly depleting their already weak physique and leading to the deterioration of their condition. Research shows that good analgesia can significantly enhance patients’ confidence and courage to resist the disease, significantly improve the quality of survival and physical quality of cancer patients, and significantly prolong the survival time of patients. Unfortunately, cancer pain patients often rely on oral or intramuscular injection of analgesic drugs, the analgesic effect is unsatisfactory and brings serious side effects, such as nausea and vomiting, constipation, urinary retention, inability to eat, respiratory depression, mental confusion and so on. How to improve the quality of patients’ survival, prolong the survival time and let patients finish the last journey of life with dignity is a major problem in the treatment of advanced cancer pain. 1. Intrathecal drug infusion system implantation Intrathecal drug infusion system implantation is an internationally respected analgesic technique for advanced cancer pain in recent years, providing an ideal solution for patients with advanced cancer pain. The technique directly injects analgesic drugs into the subarachnoid space through catheter, so as to achieve the purpose of strong analgesia, and the amount of drugs is equivalent to one three-hundredth of the dose of oral morphine. The method is safe and minimally invasive, not only providing satisfactory analgesia, but also reducing various side effects of the drug, effectively improving the quality and prolonging the survival time of patients. Intrathecal drug infusion system is regarded as the “ultimate” solution for cancer pain. Epidural drug infusion system implantation Epidural drug infusion system implantation is a special catheter placed into the epidural cavity, the other end of the catheter is connected to a miniature drug pump, and the miniature drug pump is buried under the skin. The analgesic drugs go directly into the epidural cavity. The analgesic effect of this method is as safe and effective as that of intrathecal drug infusion system implantation, but the cost is cheaper. The method of small trauma, simple operation, analgesic effect is satisfactory, less side effects, well received by patients. 3.Radiofrequency Ablation Radiofrequency ablation makes use of the difference in temperature tolerance of different nerve fibers, and achieves the purpose of pain relief by blocking the conduction of nociception through radiofrequency ablation. Under the guidance of image, our department accurately places the radiofrequency puncture needle into the corresponding area, selects the target nerves by using the nerve test method, and adopts the method of radiofrequency ablation of nerves to achieve the purpose of long-term analgesia, which effectively relieves the pain of the majority of patients suffering from cancer pain, achieves good social benefits, and is favored by the majority of patients.