Rotating shaft for small and micro aero-engine and rotor assembly with rotating shaft

The invention belongs to the technical field of aero-engines, and particularly discloses a rotating shaft for a small and miniature aero-engine and a rotor assembly with the rotating shaft. The rotating shaft is arranged to be of an axial halving structure, and the first cavity and the second cavity are arranged, so that compared with a rotating shaft of a small and micro engine adopting a solid structure in an existing scheme, the rotating shaft has the advantages that the usage amount of raw materials is less during production, the mass of the rotating shaft can be reduced, the overall mass of the aero-engine is lighter, and the production cost is reduced. Therefore, the oil consumption of the small and micro aircraft during flight is reduced; meanwhile, the first cavity penetrates through the end, relative to the rear half shaft body, of the front half shaft body, or the second cavity penetrates through the end, relative to the front half shaft body, of the rear half shaft body, so that the mass of the rot