The invention relates to the technical field of medical instruments, and particularly discloses a lumbar puncture operating table and a limiting method thereof. The lumbar puncture operating table comprises a supporting frame, a knee limiting device and a back pressing device.The supporting frame comprises a support and a supporting plate horizontally arranged on the support, and the knee limiting device comprises an electric push rod and an isolation body; the fixed end of the electric push rod is fixed to the lower portion of the supporting plate, a via hole is formed in the supporting plate, the telescopic end of the electric push rod penetrates through the via hole and extends upwards, the telescopic end of the electric push rod is sleeved with the isolation body, and a splicing groove is formed in one side edge of the supporting plate in a penetrating mode. The back pressing device comprises a fixing frame, a rotating shaft, a first telescopic mechanism, a second telescopic mechanism, a first splicing plate, a second splicing plate, a rotating mechanism and a pressing mechanism, a patient can be reliably limited, so that the body posture can be kept for a long time, the operation quality is guaranteed, the operation risk is reduced, meanwhile, thelumbar puncture operating table can be used for resting, the patient does not need to be transferred, and the safety is improved.