The high-speed railway traction power supply system operates in a harsh working environment with a complex system structure, making it susceptible to faults. The increasing burden on frontline maintenance staff necessitates prompt fault detection and analysis by field personnel when a fault occurs, enabling them to implement effective measures to restore system operation. Advances in information technology have equipped the traction power supply system with extensive monitoring and protective measures, enhancing the system’s informatization and automation, and thus increasing its complexity. A fault in the traction power supply system generates a vast amount of fault information. Personnel often struggle to handle this overwhelming data, leading to delays in fault resolution. Therefore, it is necessary to adopt effective intelligent fault diagnosis measures to assist personnel in identifying the source of faults, managing accidents rapidly, restoring power or reducing the power outage area, and minimizing the impact of faults.