Abstract: Aiming at the problems that existing energy harvesting devices are susceptible to weather, complicated installation, short life and high insulation requirements, the paper proposes a method for harvesting induced electric field energy of high voltage transmission line by using capacitor. This method of isolated electrical connection with high-voltage transmission lines has the characteristics of stable energy supply, clean energy and easy operation. According to the principle of harvesting energy by the method, the paper establishes the corresponding equivalent circuit and analyzes the characteristics of the energy harvested by the method. On this basis, a three-dimensional field calculation model is established, and the electric field distribution characteristics of high-voltage transmission lines are calculated. The effects of capacitance plate size, placement position and height on energy harvestion are discussed. Finally, based on theoretical analysis, the paper carried out an electric field test around the high-voltage transmission line of the capacitor plate. The test data was analyzed by curve fitting. Both theoretical and experimental results show that the induced voltage on the capacitor plate is a sinusoidal waveform with the same phase as the transmission line, and the highest induced voltage amplitude can reach 21.98 kV; the amplitude of the in- duced voltage will increase as the distance from the transmission line decreases and the size of the capacitor plate increases. The distance from the transmission line has a greater influence on the amplitude of the induced voltage.