Abstract: The paper selected 110 kV transmission line of mine area for simulation research object and used ATP-EMTP electromagnetic transient analysis software to establish mathematical model of transmission line struck by lightning. It made simulation analysis for influence of lightning process by changing grounded resistance value of tower and installing or not installing lightning arrester. The simulation result showed that when lightning strikes top of tower, the grounded resistance value of tower is bigger, the lightning withstand level of transmission line is lower; installing lightning arrester in transmission line can reduce overvoltage effectively.