Capacitive wireless power transfer (CPT) technology has advantages such as a lightweight coupler, low eddy current losses, and strong resistance to misalignment, which well meet the power supply needs of rotating mechanisms. However, due to the large diameter of the shaft and the time-varying self-capacitance and port mutual capacitance between the primary and secondary sides during rotation, these factors can affect the output voltage stability of the CPT system. Therefore, this paper proposes a segmented rotating CPT system based on three DC busbars. A mathematical model and equivalent circuit of the multi-port electric field coupler were established based on Z-parameters. On this basis, a high-order compensation network with constant voltage characteristics was designed and compared with the conventional structure on the receiving side. Theoretical analysis shows that the designed segmented rotating CPT system with three DC busbars solves the problem of output voltage fluctuations during over-segmentation. Simulation results indicate that the system’s output voltage drop is a maximum of 2% throughout the entire rotation process, achieving suppression of output voltage fluctuations during the full rotation of the rotating body.