Ice accident is the important factor affecting the safe operation of transmission lines. According to the principle of high-frequency excitation de-icing of overhead transmission lines, a 2D finite element model considering the coupling of electromagnetic field and thermal field of transmission lines is established. Based on the corresponding coupling field boundary conditions, magnetic field and temperature field distributions of transmission lines are obtained and the Joule’s heat and Medium’s heat, as heat sources, calculated in thermal field analysis is coupled with temperature field. The finite element ANSYS software method is applied to calculate the distribution of the temperature of ice-covered transmission lines with the applied excitation time. Moreover, the influence of different external factors on the time of ice-melting with high-frequency excitation is investigated based on this simulation model. The research results provide a certain reference value for the application of high-frequency excitation deicing technology in transmission lines. This work is supported by National Natural Science Foundation of China (No. 51307009).