Ultrahigh-voltage (UHV) transmission lines have high operating parameters and electric field intensity around the lines. It is necessary to study the electric field distribution characteristics according to different tower types and find a safe method of entering equipotential. In this article, based on the typical tower structure of UHV transmission lines, we analyzed a possible method of entering equipotential. The electric field distributions on the worker’s body under different conditions were analyzed by simulation, and safety protection measures were put forward. The study shows that entering equipotential is safe by means of a basket, insulating ladder, or climbing through a tension insulator-string. Then safety precautions were proposed for each method, and the precautions were proved safe and reliable through application, which can guide live working on UHV transmission lines.