In order to solve the slippery problem for a two-arm-wheel combined inspection robot, a magnetic maglev system based on the magnetic field of high voltage direct current (HVDC) is proposed. The magnetic system contains two parts: magnetic levitation and magnetic drive. The levitation part overcomes the gravity of the robot by the ampere force which is generated by current-carrying coils in the magnetic field of HVDC. The drive part takes the ampere force generated by current-carrying coils in the magnetic field of HVDC as the driving force. This method replaces the traditional means that the inspection robot is driven by a motor and a wheel rail. The levitation force and the driving force were calculated in theory. The relationship between the size of the physical model and the number of turns of the coil was under consideration. The COMSOL software was used to simulate the two models respectively. During the magnetic field calculation, the mean magnetization curve and the loss curve of the material are updated according to the current temperature field simulation results, and then the temperature rise is calculated based on the current magnetic field loss calculation. So repeated iterative until the end of the coupling. The simulation results show that: in the process of magneto-thermal coupling, the temperature has a significant influence on the magnetic permeability of the magnetic core, thus affecting the magnetic driving force. In view of this, the thermal-magnetic coupling simulation is performed again for the open box optimisation design of the outer box body.The results show that the magnetic levitation method and the magnetic drive method is feasible in theory, and the model is correct and effective, which is of great practical significance to the physical realization of the inspection robot.