Abstract：The statistical data of the failure of the transmission line fault shows that the damage is the main reason for the drop line of high voltage overhead transmission line. A typical high-voltage overhead transmission line was selected to use the preset type of the preset type, which was used for the observation and analysis of the heating condition of the preheating wire by Flir infrared thermograph. In order to study the effect of the skin effect on the heating phenomenon of precast wire, the ANSYS finite element software was used to simulate the magnetic field and current density distribution cloud map of the precast wire, and the data processing and analysis were carried out. Finally, combined with the typical cases, compare the simulation results and observation data this paper verified the skin effect can make accepting the silk fever and should not be ignored, when large calorific value, by pulling force more than material under the temperature after the yield point, the hinge is stretched, necking and final fracture. Research results can be applied to forecast in the running state of the hinge of gold has the flaw detection, avoid accidents caused by skin effect drops, ensure reliable connection, improve the stability of power grid operation.