The rapid arrival of the global aging era has increased the number of elderly cancer patients year by year, and the characteristics of elderly tumor patients with more comorbid diseases, less responsive organism and stronger psychological tolerance make the control of cancer pain in the elderly more unsatisfactory. Due to the complexity of cancer pain etiology and clinical manifestations, the treatment of cancer pain, like cancer, requires comprehensive treatment. For elderly patients with cancer pain, non-invasive and convenient treatments should be chosen as much as possible to achieve pain relief, improve quality of life and increase compliance with anti-tumor therapy. Besides antitumor treatment, palliative cancer pain control plays a very important role in maintaining the quality of life of elderly patients. Rational application of the principle of three-step pain relief Non-invasive drug delivery Oral and patch drug delivery should be chosen as much as possible to avoid traumatic drug delivery routes, which facilitates patients’ long-term medication use and is especially applicable to elderly patients. Injectable administration should be used as little as possible to ensure safe and effective pain relief. Timely administration of pain medication should be given regularly and “on time” rather than “on demand” or only when the pain is present. They should be given “in anticipation” of the onset of cancer pain. We should educate elderly patients so that they can overcome the long-established habit of “taking medication only when there are symptoms”. In principle, opioids can be administered directly to patients who have not been previously treated with pain medication or the WHO three-step analgesic approach, but who are already experiencing moderate or severe pain at the time of the initial visit. The duration of second-step medication can also be shortened clinically, but with attention to the safety of the medication and with the ultimate goal of rapid pain relief. Individualization of treatment, attention to specific patient details and actual efficacy The dose of pain medication should start with a small dose and gradually increase until the patient’s pain disappears, according to the patient’s needs. Instead, the dosage should not be too restrictive, leading to underdosing. However, it is common that the amount of pain medication for the elderly is low, and the effect of adequate pain relief is not achieved. Drug selection NSAID is mainly suitable for the treatment of mild pain, but it should be used with caution in elderly patients, and electrolytes and renal function should be tested at the same time of treatment. For severe pain, strong opioids such as fentanyl, morphine or oxycodone can be used for elderly patients with cancer pain. Due to changes in drug metabolism and clearance, the drug concentration is high and the duration of action is prolonged in elderly patients, so the use of opioids in the elderly should start with small doses and increase slowly. Fentanyl transdermal patches have no toxic metabolites, exact efficacy, and good tolerability, making them a better choice for elderly patients with pain. In addition, agonist-antagonists such as dextropropoxyphene and buprenorphine should be avoided in the elderly; methadone has a long half-life and unstable blood concentration; pethidine is also not recommended in elderly patients with cancer pain because of the organ toxicity effects of its metabolite norethindrone. Management of drug side effects Side effects of opioids in the elderly include constipation, nausea, vomiting, sedation, pruritus, delirium, and urinary retention, depending on their frequency. Constipation from opioid use is common in the elderly and is usually treated prophylactically with appropriate laxatives to soften stools and promote gastrointestinal motility, commonly used drugs such as senna, marijuana pills, and gastrointestinal stimulants. Nausea and vomiting may occur in elderly patients using opioids for the first time, and the symptoms usually diminish to disappear after 2 to 3 days. Small doses of antiemetics, such as gastrofacial, morpholine and, if necessary, haloperidol, may be given at the beginning of pain relief. Fentanyl transdermal patches are administered transdermally and are not absorbed through the gastrointestinal tract, so the incidence of constipation, nausea and vomiting is greatly reduced and better tolerated by the elderly. In addition, respiratory depression is the most serious adverse effect for elderly patients. Respiratory depression rarely occurs when opioid doses are gradually increased from small doses, because pain is a physiological antagonist of opioids. Occasionally, respiratory depression may be relieved with naloxone. Adjuvant medication Adjuvant therapy can be used in any stage of the three-step cancer pain treatment, which can treat specific types of pain, improve other symptoms, increase the analgesic effect of the main drugs and reduce side effects, but it is not recommended for routine use. Tricyclic antidepressants such as doxepin and promethazine are moderate-strength sedatives used to treat neuropathic pain and sleep disorders. For elderly patients, the initial dose starts at 10 mg orally at bedtime and is gradually increased. The anticonvulsant drug gabapentin is a new anticonvulsant that is effective for peripheral neuralgia due to diabetes and after treatment, and is suitable for elderly patients because of its low toxicity. It can also be used in combination with low doses of tricyclic antidepressants. Benzodiazepines can help patients reduce pain through effective sedation. Steroid hormones have adjuvant effects on pain caused by intracranial hypertension, acute spinal cord compression, bone metastasis, and hepatic peritoneal dilatation, as well as nerve injury pain caused by tumor invasion.