The invention discloses a permanent magnet synchronous motor starting mechanism. The permanent magnet synchronous motor starting mechanism comprises an impeller and a rotor, wherein the impeller is provided an installing cavity, the installing cavity is internally provided with a driving sleeve, the rotor is connected with the driving sleeve, and therefore the rotor can drive the driving sleeve to rotate; a buffering piece is installed between the driving sleeve and the inner wall of the installing cavity, the buffering piece and the driving sleeve are mutually interfered in the radial direction, the buffering piece and the inner side wall of the installing cavity are mutually interfered in the radial direction, and therefore the driving sleeve is driven to rotate and drive the buffering piece to rotate, and then the buffering piece drives the impeller to rotate. According to the permanent magnet synchronous motor starting mechanism, the buffering piece and the driving sleeve are mutually interfered in the radial direction, the buffering piece and the inner side wall of the installing cavity are mutually interfered in the radial direction, and therefore the driving sleeve is driven to rotate and drive the buffering piece to rotate, and then the buffering piece drives the impeller to rotate, so that the purpose of starting is achieved, the rotating angle of the buffering piece is large, the starting success rate is high, the damage to a motor is small, and the structure is simple.