This book comprehensively and systematically introduces the research and application of digital twin operation and maintenance technology for high-speed train traction power supply system. The book is divided into six chapters, which introduce the digital twin architecture of high-speed train traction power supply system, digital twin modeling of power supply system, multi-physical field digital twin of train key equipment, digital twin of typical train scenarios, and digital twin operation and maintenance of train traction power supply system. This book is novel and focused, the whole book is oriented to the actual engineering problems, covering the theoretical frameworks, model building, data analysis, and application practice. It extensively describes digital twin modeling and intelligent operation and maintenance methods for high-speed train traction power supply systems, proposing a novel approach of digital twin intelligent operation and maintenance based on deep learning image recognition, aiming to ensure the safe operation of high-speed trains. It could be serve as a reference book for graduate students and professionals in rail transit and power engineering.