The invention discloses a centrifugal pump back plate disassembling and assembling device and method. The centrifugal pump back plate disassembling and assembling device comprises a back plate which is provided with a connection hole, and further comprises a supporting frame and a bracket, wherein the supporting frame comprises a backup plate, a supporting plate and a limiting plate which are connected in sequence, the backup plate and the limiting plate are oppositely arranged, the backup plate is located on one side of the back plate, the limiting plate penetrates through the connection holeto be arranged on the other side of the back plate, and the supporting plate is arranged in the connection hole; and the first end of the bracket is connected with the backup plate, the second end ofthe bracket extends in the direction away from the center axis of the connection hole, and hanging holes are formed in the second end of the bracket. The centrifugal pump back plate disassembling andassembling method is used for disassembling and assembling the back plate. According to the centrifugal pump back plate disassembling and assembling device and method, the disassembling and assembling safety of the centrifugal pump back plate is improved, the time required for disassembling and assembling the centrifugal pump back plate is saved, the labor intensity is relieved, and the manpowercost is reduced.