Abstract: In order to improve and stabilize the output voltage of new energy power generation system, an ultra-high voltage coupled inductor DC-DC converter is proposed. A coupling circuit boost structure is adopted to add a new gain regulating unit to the converter. A switching clamp structure is used to reduce the voltage spike of the converter switching device, absorb the leakage inductance energy of the coupling circuit, and improve the voltage conversion efficiency. The circuit is controlled in a closed loop to stabilize the output voltage of the converter. The operating modes and state space expressions of the circuit are deduced and compared with typical boost circuits in recent years. The steady-state performance of the circuit under closed-loop control is analyzed by simulation and experiments. The results show that the converter can increase the low voltage of 18 V DC to the high voltage of 380 V stably, which lays a foundation for improving the output voltage of the new energy power generation system.