High-energy laser is utilized to instantly dissolve foreign objects entangled in high-voltage lines without damaging transmission lines. When it is found that there is a foreign object hanging on the grounding wire that affects safe operation, the operator aims at the target through a sight on the ground, controls the laser device to emit laser. Through several seconds of burning and melting, the plastic-fiber foreign object is melted off, and the laser is turned off, thus completing the entire processes of handling foreign object with electricity.