Abstract: The construction of a digital and intelligent power grid relies on a large number of distributed electrical equipment status-monitoring sensors. Improving the power supply reliability of the sensors and realizing self-powered sensing are of great significance to expanding the depth and breadth of the equipment status sensing system. In recent years, micro-nano energy harvesting methods and devices represented by nanogenerators have attracted widespread attention. They can convert diverse and dispersed mechanical energy, thermal energy, electromagnetic energy, etc. into electrical energy, by combining with micro-energy storage components and low-power micro-nano devices for self-powered sensing. This article focuses on the theme of micro-nano energy harvesting for self-powered electrical equipment status sensing. Firstly, the distribution characteristics of micro-energy in electrical equipment and its operating environment are introduced. Then, the principles and characteristics of micro-nano energy harvesting methods represented by thermoelectric nanogenerators, triboelectric nanogenerators, piezoelectric nanogenerators, magnetic field energy harvesting generators, and hydrovoltaic generators are summarized, and their applicability in electrical equipment scenarios is analyzed. Furthermore, the latest progress in micro-energy harvesting and self-powered sensing of electrical equipment based on micro-nano energy devices is reviewed, and the main technical difficulties and potential solutions in the field are proposed. Finally, the prospects in development trends of micro-nano energy harvesting methods and devices are put forward, which is expected to provide reference and guidance for self-powered status monitoring and digital intelligence development.