Abstract: During analgesic treatment of one patient with bone metastasis of rectoanal malignant tumor with refractory pain, the nature and degree of pain and adverse reactions caused by drug treatment were analyzed and evaluated by clinical pharmacist, and the suggestion of individualized analgesia administration was put forward. After treatment, the pain control was stable and the adverse reactions were tolerable. Participation of clinical pharmacists in drug treatment of patients with refractory cancer pain can provide individualized treatment suggestions, and standardize the rational use of analgesics in clinic.