The invention relates to a permanent-magnet synchronous motor, which comprises a rotor and a stator arranged outside the rotor, the rotor comprises a rotor core, the rotor core is provided with magnet slots, and magnetic steel groups are inserted in the magnet slots. The permanent-magnet synchronous motor is characterized in that the magnet slots are evenly arranged along the circumferential direction of the rotor core, the magnet slots are first magnet slots and second magnet slots, the second magnet slots are closer to the periphery of the rotor core than the first magnet slots, the number of the first magnet slots are half of the number of the second magnet slots, the first magnet slots and the second magnet slots staggerly correspond to each other, and moreover, the first magnet slots are arranged between the second magnet slots corresponding to the first magnet slots and a rotary shaft of the rotor core; the outer magnetic steel groups are arranged in the second magnet slots, and the inner magnetic steel groups are arranged in the first magnet slots. The motor disclosed by the invention is put forward under the current special requirement of power systems of electric vehicles on driving motors, and the motor has the advantages of high power density, wide speed regulation range and low popularization cost.