The present invention provides a permanent magnet synchronous motor, belonging to the technical field of motors. The permanent magnet synchronous motor is characterized by: adoption of a solid shuttle-shaped rotor structure; a large radial air gap and an axial non-constant air gap; a permanent magnet adopting a radial buried structure; a starting squirrel cage embedded on the rotor; and the rotor and a stator both provided with corresponding ventilation ducts that facilitate cooling air which passes through the large radial air gap to take away heat of the surface of the solid rotor and heat of the stator itself. The permanent magnet synchronous motor in the invention not only solves a problem of starting difficulty in a permanent magnet motor having a conventional laminated rotor, but also solves a problem of heat dissipation difficulty in a permanent magnet motor having a conventional solid rotor. The permanent magnet synchronous motor in the invention with a starting torque from 2.0 to 3.0 further overcomes a problem of easy demagnetization of the permanent magnet caused by a too high temperature of the rotor.