A permanent magnet motor, a compressor and an air conditioner are disclosed. The permanent magnet motor has a stator and a rotor. The stator has a stator core and a stator winding. The rotor is spaced apart from the stator in an inner-outer direction. The rotor has a rotor core and a permanent magnet embedded in the rotor core. A maximum distance between an outer peripheral contour of a cross section of the rotor and a center of the cross section of the rotor is D1, an axial length of rotor core is L, and a rated power of permanent magnet motor is P. D 1, L and P satisfy: D1/L≥1.7 and P/(D12×L)≥8.5, and the unit of P is W, and the unit of D1 and L is cm.