Abstract: Magnetic field energy harvesting shows promise for powering wireless sensors in the energy internet. The magnetic field energy harvester (MFEH) needs to be combined with series-matched capacitors, rectifier bridge, and DC-DC converter to achieve maximum power extraction and transmission. However, the existing low-order simplified models cannot adequately analyze the output characteristics of the high-order nonlinear circuit comprising the MFEH, series-matched capacitors, and rectifier bridge. Due to the resonance between the series-matched capacitors and the equivalent inductor, the open-circuit voltage of the rectifier bridge has the potential to exceed the peak AC open-circuit voltage of the MFEH, which cannot be simply equated to the open-circuit voltage of the rectifier bridge without careful consideration. The phasor method and Gauss-Seidel iterative method are employed to establish an accurate model for the steady-state optimal output voltage of the high-order nonlinear rectifier bridge. The transient open-circuit output characteristics of the rectifier bridge are extracted using the fourth-fifth order Runge-Kutta adaptive method. Furthermore, a self-powered low-power open-circuit voltage method for the maximum power point tracking scheme using free-standing MFEH is implemented. The research presented establishes a theoretical foundation for determining the maximum power point of the MFEH system and designing the parameters of the open-circuit voltage method.