A motor rotor comprises a mandrel, a vortex sleeve disposed on the partial periphery of the mandrel and a permanent magnet arranged on the mandrel. A channel is arranged inside the mandrel, a gas-liquid core is arranged in the channel, and the channel is communicated with the vortex sleeve. The tail ends, in the length extension direction of the mandrel, of the permanent magnet are respectively provided with a magnetism isolation ring, and the periphery of the permanent magnet and the magnetism isolation rings is sleeved with a protective sleeve. The vortex sleeve is arranged outside the protective sleeve, and a gap is reserved between the vortex sleeve and the protective sleeve. The vortex sleeve, the protective sleeve and the channel of the mandrel form a closed cavity. The motor rotor further comprises a heat dissipation element which is arranged at the tail end of the mandrel and used for dissipating heat. According to the motor rotor, the temperature of the rotor (the permanent magnet) can be effectively lowered, the power consumption of a motor is reduced, and the efficiency of the motor is improved.