Abstract: With the continuous growth of renewable energy installed capacity, flexible DC transmission technology has gradually become the primary solution for long-distance transmission of renewable energy. This technology is evolving from mature point-to-point structures to multi-terminal and networked DC grid configurations, enabling more efficient energy optimization and allocation. In this process, high-voltage, high-capacity DC/DC converters serve as the core equipment for DC voltage transformation and DC power flow control. The potential application scenarios and technical requirements of high-voltage, high-capacity DC/DC converters are firstly elaborated. The working principles, existing topologies, and technical-economic performance of both isolated and non-isolated high-voltage, high-capacity DC/DC converters are secondly summarized and compared. Based on this, the typical applications of high-voltage, high-capacity DC/DC converters in multi-port evolution, high-ratio evolution, and DC power flow control are further introduced. Finally, the future research directions for high-voltage, high-capacity DC/DC converters are proposed.