To address the issue of low power in electric field energy harvesting devices, this paper proposes an optimization method for powering monitoring equipment based on resonant capacitor electric field energy harvesting. By using a transformer to increase the equivalent impedance of the load and employing parallel resonance, the energy harvesting power is enhanced. Coupling capacitance, a key factor influencing energy harvesting power, is analyzed using finite element simulation to examine the impact of different electrode installation methods on the coupling capacitance value. Additionally, a three-dimensional mesh electrode structure is proposed, which not only increases the coupling capacitance but also improves the spatial utilization of the energy harvesting device. To achieve optimal energy harvesting efficiency, the study shows that the excitation reactance of the transformer needs to be greater than 0.3 times the \(\left|{Z}_{m}\right|\) . Finally, by adjusting the transformer turns ratio and selecting appropriate compensation capacitors, the voltage and power requirements of different loads can be met, thereby enhancing the system's applicability and flexibility.