A homopolar direct current electromagnetic motor (HET) and an application system thereof are provided. The homopolar direct current electromagnetic motor includes two rotors, a stator, an external auxiliary system and an adjustment control system. Each of the rotors has one or more axisymmetric-shaped rotor magnetic conductors (3), the stator has one or more direct current excitation coils (9) wound around a central axis of rotation (1). A main magnetic circuit (22) is guided to be a closed ring by the axisymmetric magnetic conducting structure of the rotor and the stator. There are at least two main magnetic circuits, the main magnetic circuits passing through rotor magnetic conductors and stator magnetic conductors (7), and at most one of main magnetic circuits passes through rotor magnetic conductors of the motors simultaneously. There is a closed main current (IO) loop (23), the loop is connected with all of the rotor magnetic conductors, a rotor conductor (4), a dynamic/static circuit connecting medium (5), stator conductors (6, 11) and stator magnetic conductors in series or series-parallel. A direction of a main current on the rotor magnetic conductors is perpendicular to a direction of magnetic flux (#) on meridian plane. The main current and magnetic torque of each of the rotors is controlled through adjusting currents (I1, I2, ...) of direct current excitation coils.