Lightning is one of the main reasons that threaten the safty and stablity of 500 kV transmission lines

where the line trip due to lightning shielding failure occurs very frequently.This problem is especially serious in moutain areas.This paper presents the small-scale model experimental results of lightning shielding performance of transmission lines in mountain areas

for further study of the lightning shielding performance of UHV transmission lines.The experiments in this paper are carried out with such factors as the gradient of the hillside

the depth of the valley

and the non-vertical leader.The experimental results show that the risk of shielding failure of UHV transmission lines is much higher in mountain areas than in plain areas.