Three-step pain relief refers to the selection of the first, second and third step pain relief drugs according to the degree of mild, moderate and severe pain of patients. The specific principles include: (1) Oral administration Oral administration as much as possible, and non-invasive administration method is advocated. (2) Administering drugs on time, not on demand. For example, morphine 10mg q4h orally, or Meclizine 30mg q12h orally, or Doregis 2.5mg q72h. (3) Administering drugs according to different steps according to the degree and nature of pain. The first step: non-opioid drugs, mostly referring to NSAID drugs, are effective for mild pain, and can enhance the effect of second and third step drugs, with capping effect. When the pain is not relieved, it is not advisable to switch to another NSAID drug, but should be directly promoted to the second step. Second step: weak opioids, such as codeine, dihydrocodeine, tramadol, etc. The first use of weak opioids plus NSAID has good results, and there are many combinations of weak opioids and NSAID drugs. The safe dose of weak opioids is often limited by the NSAID dose with capping effect in the combination. The third ladder: strong opioids, represented by morphine, with many drug types and dosage forms, rational use will make more than 90% of patients with moderate to severe pain free from pain. No capping effect, i.e. no ceiling effect. The main drugs are morphine (there are a variety of dosage forms, such as injection, immediate release, extended release oral morphine), fentanyl transdermal patch (Doregis), methadone, pethidine, etofil, oxycodone. (4) Individualization of medication (5) Attention to specific details Such as attention to the management of adverse reactions.