Specific methods of three-step treatment for cancer pain: In the first step, for mild pain, non-opioid analgesics are used, and the representative drug is aspirin. Ibuprofen and aminophen para-acetate, which have mild gastrointestinal reactions, can also be used. In the second step, in mild and moderate pain, non-opioid analgesics alone cannot control pain, and weak opioids should be added to improve the analgesic effect. The representative drug is codeine. In the third step, strong opioids are used, and the representative drug is morphine. The choice should be based on the intensity of pain (such as those with moderate or severe cancer pain) rather than on the prognosis of cancer or the time frame of life. Extended-release or controlled-release dosage forms are commonly used. In cancer pain treatment, the combination of drugs is often used, that is, some adjuvant drugs are added to reduce the dosage and side effects of the main drug. The adjuvant drugs include: (1) weak tranquilizers, such as diazepam and eszopiclone; (2) strong tranquilizers, such as chlorpromazine and haloperidol; (3) antidepressants, such as amitriptyline. Strictly following the three-step treatment method for cancer pain will achieve good treatment effect and reduce the occurrence of opioid addiction.