Abstract: Provided are an electric motor having an adjustable magnetic field, and a vehicle. An excitation ring assembly of the electric motor includes an excitation ring having an outer ring wall and an inner ring wall and an excitation winding. An excitation rotor of the electric motor includes first permanent magnets and a rotor core provided with first and second magnetic pole forming sections that are circumferentially arranged alternately, a first magnetic pole cooperating portion corresponding to the first magnetic pole forming section, and a second magnetic pole cooperating portion corresponding to the second magnetic pole forming section. The first permanent magnets correspond to the first and second magnetic pole forming sections. A second air gap is defined by the outer ring wall and the first magnetic pole cooperating portion and a third air gap is defined by the inner ring wall and the second magnetic pole cooperating portion.