Abstract: The three-pole radial-axial hybrid magnetic bearing is driven by three-phase inverter in the radial direction, because the three-phase inverter has the advantages of small volume, low power lost and low costs. However, the sum of three-phase currents of the inverter must be zero, which has effects on the radial carrying capacity of the magnetic bearings. The structure and work principle of three-pole radial-axial hybrid magnetic bearings were first introduced and the mathematic model of fluxes in air gaps was built. According to the model, the conditions of producing maximum suspension forces in positive and negative directions of rectangular coordinate axes were analyzed and the equations of maximum suspension force are derived. To proving the correctness of the analysis, finite element simulations were calculated by software ANSOFT and the experiment data were measured. The simulation and experiment results agree with the analytical results. The works of this paper are instructive and meaningful to the design, installation and control of three-pole magnetic bearings.