Abstract: With the accelerated development of the Power Internet of Things and the digital-intelligent transformation of transmission and distribution equipment, the number of distributed sensors in power systems has surged. Yet, the reliable power supply for these sensors has become a critical bottleneck restricting the breadth and depth of condition monitoring for power equipment. Self-energy harvesting and self-power sensing technologies based on micro-energy collection, boasting strong scenario adaptability and low maintenance costs, are expected to address this pain point. Electromagnetic fields(EMF), as widely existing and most representative stable energy sources in power equipment and systems, make EMF-based energy harvesting a promising approach to achieve large-scale distributed self-powered sensing. The latest advances in EMF energy harvesting methods and technologies for power equipment are reviewed, focusing on two primary energy harvesting pathways: electric and magnetic fields. The key technologies, principles, and applications for four typical scenarios of power equipment, namely transmission lines, power cables, substations, and converter stations are summarized. Finally, challenges and development trends are discussed from five dimensions: device structure optimization, multi-energy complementarity, output performance enhancement, engineering application, and intelligent development, providing a reference for self-powered distributed sensing of power equipment.