Overhead transmission lines are lifeline projects，and ice load is one of the greatest threat to transmission lines safety. On the basis of the project of Chinese Grid Xinjiang Electric Power Research Institute，the finite element numerical simulation models of overhead transmission lines were established by means of ANSYS software. Using the technique of birth and death of the element for ices，the finite element analyses of zippered and simultaneous ice-shedding vibrations were carried out. By analyzing the modeling parameters of the overhead transmission lines，the influence of altitude difference on the vibration response of single-span ice overhead transmission lines was studied，and compared with the results of the experiment of the scaled model. The results show that the simulations of the zippered and simultaneous ice-shedding are well matched with the experimental results and the discrepancies are less than 5%，which proves the accuracy of the simulation method. If the altitude of two suspension points is the same，the maximum jumping height first increases with the deicing speed and then is maintained at a constant value，while the maximum force is not affected by the deicing speed. If the altitude of the two suspension points is different，the maximum jumping height increases exponentially with the increase of altitude，and the jumping height of the zippered ice-shedding gradually approaches the value of simultaneous ice-shedding when the initial stress is constant. The existence of altitude aggravates the upturn of lines，and the maximum jumping height is greater than the sag of iced line. Meanwhile，the occurrence of upturn can be reduced by decreasing the initial stress and icing thickness of transmission lines.