Clinically, different patients perceive cancer pain differently and have individual differences. Certain patients do not feel pain significantly, while certain patients feel painful. There are generally the following methods to assess pain level clinically: 1. numerical scoring method: 0-10 represents the degree of pain, 0 means no pain, 10 means the most painful. The pain assessment scale can roughly assess the patient’s pain level; 2. Expression scoring method: Expression assessment method is used for patients who are not able to communicate normally; 3. Complaint scoring method: If the patient’s pain does not affect his or her sleep, the pain level is generally mild. If the sleep is slightly affected, but there is no need to use painkillers or the requirement to use painkillers is not very strong, the pain is moderate. If sleep is severely disturbed, pain medication is strongly required, or the use of pain medication is not effective, the pain is severe. Pain assessment can guide subsequent treatment, including medication selection and dose determination.