Beidou chip plays an essential role in monitoring Overhead transmission line tower deformation and galloping, but the power transmission line electromagnetic field will interfere with the reliable operation of Beidou chip. It is significant to get an accurate calculation, which is important to the operation reliability and the optimization of the installation position. With the establishment of a finite element simulation model, the lower part of the 500kV transmission line tower electric field and potential distributions are studied. Based on the simulation results, near Beidou chips’ typical position, the effects of installation position on the electric field are discussed. By setting three kinds of line voltage, this paper obtains cloud atlas of the lower parts of the tower and gets more reliable results. The research results in this paper can provide guidance for installing Beidou chips on transmission line towers and improving operational reliability.