The invention provides an electrombile wheel hub motor with a centralized excitation function. The electrombile wheel hub motor comprises a stator iron core, an outer rotor iron core, excitation windings, armature windings and a shaft, wherein seven rotor poles which are of convex pole type structures are arranged at the inner side of the outer rotor iron core, and the pole-arc coefficient of each rotor pole is 0.5; two excitation poles wound by the excitation windings and four armature poles wound by the armature windings are arranged on the stator, and the excitation poles and the armature poles respectively adopt stator poles which are of convex pole type structures; the two excitation poles are distributed at the interval of a 180-degree mechanical angle, and the pole-arc mechanical angle of the excitation poles is 33.6 degrees; two armature poles are arranged at both sides of each excitation pole, and the pole-arc mechanical angle of the armature poles is 25.6 degrees; a stator groove for placement of the armature windings and the excitation windings is arranged between each armature pole and the corresponding excitation pole, and the mechanical degree of an opening of each stator groove is 28.7 degrees. The electrombile wheel hub motor has the advantages that when the motor is used as a power generator to run, the output voltage at different rotation speeds can be controlled by adjusting the excitation current, and then the brake energy is recycled for charging a storage battery of an electrombile; when the motor is used as an electric motor to run, the output torque of the wheel hub motor can be controlled by adjusting the sizes of the excitation current and the armature current.