The bipolar DC microgrid system represents an innovative power supply architecture offering high reliability, flexibility, and efficiency. Building upon advanced research findings, this study proposes a three-winding coupled-inductor bipolar-output high-gain DC-DC converter. By incorporating coupled inductor coils and a switched-capacitor boosting mechanism into a bipolar-output three-level Boost converter topology, the proposed converter achieves low input current ripple and reduced stress on switching devices. The output voltages can be regulated via the switch duty cycle and the turns ratio of the coupled inductor. This paper presents the topology derivation, operating principles, and mode analysis of the proposed converter. The voltage gain, along with the voltage and current stresses on key components, is theoretically derived and numerically evaluated. A comparative analysis is conducted against existing high-gain DC-DC converters to highlight the advantages in efficiency and performance. Furthermore, the efficiency of the converter is thoroughly analyzed. An experimental prototype was developed to validate the converter′s performance. The prototype operates at a switching frequency of 50 kHz, with an input voltage of 28 V and an input power of 200 W, delivering bipolar output voltages of +190 V and -190 V. A suitable input inductor is selected based on the desired input current ripple ratio. Full-load tests (200 W) were conducted at input voltages of 24, 28, and 32 V, with the system successfully boosting to a total output voltage of 380 V. Experimental waveforms of input current and output voltage are presented under both half-load and full-load conditions, demonstrating efficiencies of 95.65% and 93.63%, respectively. These results confirm that the proposed converter performs efficiently under high-frequency operation, making it highly suitable for applications requiring high efficiency and compact design. The converter shows strong potential for widespread application and holds significant research value in the field of electric power systems.