This paper focuses on the flux regulation principle in a novel hybrid-magnetic-circuit variable flux memory machine (HMC-VFMM). The proposed HMC-VFMM combines the distinct advantages of series and parallel hybrid magnet circuits, namely, wide flux adjusting range in parallel type and excellent on-load demagnetization withstand capability in series type. A simplified Fourier-series based hysteresis model is developed and numerically programmed in finite-element software in order to track the movement of the working point of low coercive force (LCF) magnet accurately. This allows a general analysis solution to investigate the flux regulation characteristics of the proposed HMC-VFMM. In addition, the frozen-permeability method (FPM) is employed to extract the actual paths of the magnetic fields due to different excitations. Finally, the flux regulation experiments of the HMC-VFMM prototype are established to confirm the merits of the proposed design in terms of the relative overlapping between one-way and bi-directional magnetization characteristics, which is beneficial for online magnetization state (MS) manipulation.