I. Oral administration. Simple, non-invasive, easy for patients to use long-term, and suitable for most pain patients. Second, the drug is given on time. Note: it is “on time”, not only when the pain is given. Third, according to the three-step principle of drug administration. According to the different degrees of pain, the patient should be given different steps of medication. IV. Individualized medication. The dose of medication should be determined according to the individual patient’s condition, and the purpose is to be pain-free, and the amount of medication should not be too restrictive and lead to underdosing. V. Closely observe the changes of patients after medication, promptly deal with the side effects of various drugs, observe and evaluate the efficacy of drugs, and promptly adjust the dosage of drugs.