Based on switched inductors and switched capacitors, a novel high-gain DC/DC converter with expandable structure is proposed. The article firstly analyzes the current research status of high-gain DC/DC converters; secondly, it analyzes the series topology based on switched inductors and switched capacitors; and then it analyzes the proposed novel high-gain converter based on switched inductors and switched capacitors. After the analysis, the working principle and main waveforms of the converter are studied; the voltage gain of the novel high-gain converter and the voltage stress of the switch tube and diode are studied; the state-space equation is modeled for the novel high-gain converter, the PI regulator is designed, and finally the Simulink closed-loop control system simulation of the proposed system is carried out. The simulation results show that the closed-loop system has excellent dynamic and steady-state performance, and achieves an output of 20 times the voltage gain. The novel DC/DC converter has the advantages of expandable structure and high gain.