At present, leg pain caused by cancer is collectively referred to as cancer pain in clinical practice. Cancer pain is characterized by heavier attacks at night than during the day, and cancer pain is treated as a disease. Depending on its nature, cancer pain can be further categorized into injury sensory pain and neuropathic pain. Injury sensory pain manifests itself as vague pain, tugging pain, and visceral pain. Neuropathic pain is mostly caused by damage or dysfunction of the nervous system, which is not only accompanied by the clinical manifestation of pain, but also accompanied by the clinical manifestation of sensory hyperalgesia or sensory hypersensitivity. Either type of pain is caused by the cancer itself or by cancer treatment, so the pain can be controlled by either controlling the cancer or applying pain medication to control the pain, a combination of both approaches.