The invention relates to a low-harmonic-wave magnetizing method and apparatus for a permanent-magnet rotor. A plurality of modulation type magnetizing poles are arranged and thus the whole magnetizing pole surface is divided into a plurality of tooth-shaped magnetizing poles; a central angle occupied by each magnetizing pole and a magnetizing potential forms a low-harmonic-wave proportional relation to realize a modulation type permanent-magnet rotor magnetizing pole. A low-harmonic-wave magnetizing permanent-magnet rotor magnetizing apparatus is prepared by using the modulation type magnetizing poles, a magnetizing coil, and magnetizing currents and thus the magnetizing poles apply modulation type magnetic filed effects on permanent-magnet magnetic powder during the permanent-magnet rotor moulding process, so that modulation arrangement is carried out on the magnetic domain inside the magnetic powder material in the permanent-magnet rotor. When the permanent-magnet rotor is installed into the motor after moulding, a generated air-gap magnetic-filed waveform is close to a sinusoidal wave. According to the invention, a defect of non-sinusoidal-wave distribution at the air gap magnetic field according to the existing permanent-magnet rotor magnetizing method can be overcome; the harmonic wave magnetic field effect can be reduced; the performance of the permanent-magnet rotor can be improved; the vibration and noises of the permanent-magnet rotor can be reduced; and the operation stability and reliability of the permanent-magnet rotor can be enhanced.