Leg pain caused by central nervous system leukemia can usually be relieved by intrathecal injection and radiotherapy. 1. Intrathecal injection: chemotherapeutic drugs such as cytarabine and methotrexate are injected into the cerebrospinal fluid through lumbar puncture and glucocorticoid drugs such as dexamethasone are used in combination. The drugs enter the cerebrospinal fluid directly to kill the leukemia cells, so as to cure the CNS leukemia, and the symptoms of leg pain can be relieved naturally. 2. Radiotherapy: killing leukemia cells through whole brain and whole spinal cord radiotherapy to relieve leg pain symptoms. There may be other treatments for CNS leukemia, but it should be noted that intravenous infusion of chemotherapy drugs cannot pass the blood-brain barrier, so it is difficult to have a therapeutic effect on leg pain caused by CNS leukemia, so it is not recommended to use it. Leg pain caused by central nervous system leukemia should go to the hospital in time, and standardized treatment under the guidance of the doctor. The above drugs should be used under the guidance of a doctor, avoid self-medication.