This paper investigates the characteristics of the electric field distribution of 220kV transmission lines. Using the finite element simulation software COMSOL, the study simulates the electric field distribution around the tower and conductor surfaces under the drum-type arrangement of a double-circuit 220 kV transmission line on the same tower. It explores the variations in electric field distribution under different configurations and their impacts on the environment and safety. The analysis focuses on inverse phase sequence configuration, the structural impact of towers, the choice of conductor size and split spacing, and the conductor-to-ground height. The study shows that, thanks to the optimization of voltage phase vector differences, an inverse sequence arrangement can significantly reduce the ground-level electric field intensity. The impact of conductor size is minor, while appropriate choice of split spacing can effectively control the electric field intensity. Moreover, the conductor-to-ground height is the most significant factor affecting the ground-level electric field. Adjusting the vertical layout of conductors can optimize the electromagnetic environment and enhance safety. This research provides practical guidance and recommendations for the electric field optimization of 220kV transmission lines, contributing to the environmental compatibility and operational safety of transmission systems.