To study the influence of vertical wind speed on the wind-induced swing of jump lines in mountainous micro-topography, the vertical wind load on the conductors, jump lines, and insulator strings was analyzed based on the rigid bar method. The maximum displacement of wind-induced swing at the jump lines was determined as the index of wind-induced swing. The geometric transform relation of the static balance plane of jump lines was established before and after the wind load. Then the wind-induced swing state equation was proposed considering the influence of vertical wind speed. A terrain model with a radius of 5 km was established, including the accident site of the wind-induced swing of jump lines and the micrometeorological station. The wind speed of the accident site was deduced from the wind speed of the micrometeorological station by using the numerical simulation method to obtain the accident wind speed of wind-induced swing considering the influence of the micro-topography. The parameters of the accident line and the vertical wind speed were substituted into the wind-induced swing state equation to obtain the critical horizontal wind speed of the wind-induced swing. Then the reliability of the wind-induced swing state equation was verified by comparing the accident wind speed and the critical horizontal wind speed. Finally, the influence of variable vertical wind speed on the critical horizontal wind speed of wind-induced swing was analyzed according to the wind-induced swing state equation. The results showed that with the increase in vertical wind speed, the critical horizontal wind speed of wind-induced swing decreased linearly. When the wind attack angle was 20°, the critical horizontal wind speed could be reduced by 16%. Therefore, the critical horizontal wind speed of the wind-induced swing was much safer considering the influence of vertical wind speed which should be considered in the design of jump lines for mountainous areas.