China's vast territory and complex climate make the operating environment for high-speed rail challenging. The high-speed railway has a wide range of lines, and the climate conditions along the line are very different. The on-board high-voltage equipment is affected by multi-physical coupling stress and environmental factors (dust, haze, rain, etc.), which is easy to lead to insulation aging and threaten the safety of high-speed rail. The failure of power supply equipment accounts for a high proportion, which seriously affects the train operation. As the core system of high-speed train, traction power supply system needs large capacity power supply and efficient transmission performance. With the development of technology, digital twins are integrated with high-end equipment operation and maintenance, promoting the transformation of operation and maintenance mode to intelligence. Under the background of digital twin technology, the mechanism model and real-time data are fully utilized to achieve high-precision and high-reliability mapping and evolution, and provide support for physical system state assessment, fault warning and operation and maintenance decision, which is of great significance for improving the operation and maintenance level of high-speed trains.