Conventional manual installation and removal of grounding wires on ultra-high and extra-high voltage transmission lines involve significant safety risks and low operational efficiency. To address these challenges, an intelligent UAV-based system was developed for automated grounding operations. The proposed system integrates a motor-driven clamping mechanism for both conductors and cross-arms, a winch-based cable drive, an external torque compensation unit, and a specialized suspension interface, all managed by an integrated control module. Precision mechanical design and system integration enhance both automation and operational reliability. Field tests validated the device’s capability to execute operations without auxiliary ground tethers. The conductor-end and cross-arm clamping forces reached ≥20 kg and ≥40 kg, respectively, with a total operation time under 20 min. These results demonstrate reliable operation and adaptability in practical engineering applications, effectively addressing the safety and efficiency limitations of traditional methods.