Four months after leukemia transplantation, if there is no obvious disease recurrence or central nervous system leukemia manifestation, there is no need to do lumbar puncture again. However, if there are discomforts, such as recurrent headache, dizziness, etc., the doctor will conduct standardized examination and treatment according to that patient’s condition. 1. There are many types of leukemia, and depending on the type, the efficacy after transplantation will be different. For example, if the patient has acute lymphoblastic leukemia, which is prone to the phenomenon of central nervous system infiltration, in order to know whether there is central nervous system infiltration in time, lumbar puncture operation is needed, and then the corresponding medical measures can be taken in time, such as intrathecal injection of methotrexate, dexamethasone and so on. 2. 4 months after leukemia transplantation, if there is no obvious disease recurrence or central nervous system leukemia manifestation, there is no need to do lumbar puncture again. 3. 4 months after leukemia transplantation, if there is any discomfort, such as recurrent headache, dizziness, etc., lumbar puncture examination is performed to check whether there is any progression of the disease on the one hand, and on the other hand, if there is central nervous system infiltration before transplantation, lumbar puncture examination can be performed to check the alleviation of central nervous system infiltration and its recovery after transplantation. Specific diagnosis and treatment need to be carried out under the guidance of physicians.