Multi-stage pump flat key dismounting and mounting device

The utility model belongs to the technical field of flat key disassembling and assembling tools, and particularly relates to a multi-stage pump flat key disassembling and assembling device which comprises an upper top plate, a lower pressing plate and supporting bolts, the upper top plate and the lower pressing plate are in a circular ring shape, and the inner diameter of the upper top plate and the inner diameter of the lower pressing plate are equal to the diameter of a pump shaft. The upper top plate and the lower pressing plate are coaxially arranged outside the pump shaft in parallel, two sets of concave key grooves distributed in a bilateral symmetry mode are formed in the inner side of the upper top plate and the inner side of the lower pressing plate, and each set of concave key grooves comprises two concave key grooves distributed in an up-down symmetry mode. The upper top plate and the lower pressing plate are fixedly connected through a supporting bolt and a limiting nut. When the multi-stage pump