The utility model discloses a large -scale water -pumping energy storage unit rotor, including the yoke with along the magnetic pole of yoke periphery even interval arrangement, have along the even interval arrangement of axial in the clearance of two adjacent magnetic poles two sets ofly at least to be used for preventing that the magnetic pole from removing the tight subassemblies in telescopic top, the flexible direction of the tight subassembly in telescopic top is perpendicular with the radial direction of rotor. This rotor has simple structure, simple to operate, joint strength height, can overhaul the advantage of maintaining the degree of difficulty and intensity of labour by greatly reduced.