A dual-speed single-phase AC motor, including: a stator, including a stator core, and a coil winding, including a starting winding, a first main winding, and a second main winding, a rotor, and a starting circuit, including a rectifying and voltage-stabilizing circuit, a detecting circuit, a voltage comparison circuit, a first switching circuit, a second switching circuit, and a third switching circuit. The number of poles of the starting winding is the same as that of the first main winding. The number of poles of the first main winding is less than that of the second main winding.