Abstract: In traditional transmission line inspection, defect discovery mainly depends on manual experience, resulting in low inspection efficiency, insufficient coverage of key parts, and delayed identification of hidden hazards. To improve the active defect discovery capability of transmission lines, this paper proposes a UAV-based intelligent inspection technology. This technology optimizes standardized operation procedures, constructs typical defect inspection scenarios, and formulates differentiated inspection strategies. It enables active inspection of conductors, ground wires, insulators, fittings, and line corridor hazards. Based on field application, this paper analyzes the technology in terms of operation efficiency and defect identification performance, and verifies its practicality and engineering application value.