The World Health Organization’s recommended three-step pain relief principles for malignant tumors mainly include: oral administration, on-time administration, administration by step, individualization of medication, and attention to medication details. 1. oral administration, in the treatment of drugs that can be applied orally, it is recommended that oral administration should be the mainstay, and the use of injections and subcutaneous injections should be reduced as much as possible. Patients with oral difficulties can use some of the patches to solve the patient’s route of medication. 2, on-time administration, mainly prompting patients to give drugs according to the half-life of the drug, according to the time of treatment, rather than to give drugs on demand, can maximize the control of patients’ pain, reduce the time of explosive pain, and reduce the occurrence of drug resistance. 3, according to the step of drug administration, is better to assess the patient’s pain level, according to the patient’s pain, the administration of the corresponding corresponding drug. Generally speaking, nowadays, the second-order drugs are used to weaken the treatment, and morphine-based drugs can be used for patients with moderate pain.4. Individualized medication is mainly reflected in giving different medication to each patient to maximize the patient’s treatment.5. Pay attention to the details of individualization, mainly for the different adverse reactions caused by drugs, and give detailed observation to maximize the satisfaction of therapeutic pain and reduce the occurrence of adverse drug reactions.