The invention relates to a power wheel of a hub motor which comprises a wheel hub, a wheel rib, a wheel felloe of a vehicle and vehicle tyres, a vehicle shaft, a bearing and a connecting disk supported by the bearing which are arranged inside, as well as a motor primary stator, a stator frame, a frame seat, a stator-fastening yoke, a stator winding, a motor secondary rotor, a rotor-fastening yoke, a rotor frame, a motor inter-air space, a motor rotor bracket and connecting bolts which are fixedly connected on the vehicle shaft. The power wheel uses the advanced techniques of computers, frequency conversion, voltage regulation and inversion, etc. for implementing the control and the driving of the hub motor, thus outputting the torque which is large enough to satisfy the starting, grade climbing and high-speed driving requirements of electric vehicles. The integrated mechanical and electric structure design of the invention has novel conception, advanced techniques and great practicability; the invention has simple and reliable structure, low cost, convenient production and installation. The invention can conveniently form the wheel power system of the hub motor of electric vehicles so as to promote the quick development and improvement of electric vehicles.