The utility model discloses a motor rotor with high stability, which comprises a shaft and a rotor body arranged on the outer side of the shaft, and micro-channels are symmetrically arranged in the shaft. A cavity of a U-shaped structure is formed in the middle of the shaft, a
piston block slides in the cavity, inlet and outlet pipes extending to the outer side of the shaft are fixedly arranged at the two ends of the cavity, sealing pieces are arranged at openings of the inlet and outlet pipes, and the cavity is filled with fluid media. By means of the structure, a balance
system is formed by the U-shaped cavity and the
piston block, the
mass distribution of the rotor can be adjusted, the
mass deviation can be compensated to restrain vibration, and the
dynamic balance precision is improved; the spiral micro-channel is matched with the
graphene heat-conducting film and the rotor
fan blade, so that a good heat dissipation structure can be formed, the rotor is cooled, local overheating deformation is avoided, efficient heat dissipation is achieved, and the performance of the rotor is improved.