Abstract: In response to the safety issues caused by the arcing of heavy haul trains under lightning strikes, the actual traction system is taken as a reference, and a comprehensive model of the pantograph network arc of the traction system is established under lightning current and pantograph lowering motion environment through simulation. Based on two aspects of locomotive operation and arc characteristics, the changes in macro level power and high-voltage rectifier side current are studied. At the same time, the dynamic characteristics of the pantograph network arc are analyzed, and the impact of lightning strikes on the dynamic characteristics of current collection for heavy-duty locomotives with a speed of 73 km/h is evaluated. Through simulation and comparison, it is found that the arc in the lightning induced pantograph drop causes the pantograph power supply voltage to charge the parasitic capacitance of the cable. Due to the inductance of the locomotive high-voltage end equipment and the pantograph, the oscillation fluctuations and overvoltage peaks of the equivalent circuit are affected. There is hysteresis in the arc of lightning striking and lowering the bow. The input lightning current can cause changes in the inductance and capacitance of the traction system, as well as the capacitance of the plasma formed by the arc, thereby increasing the storage capacity of the arc and the sensitivity of the arc capacitance to voltage. Theoretical data for correctly evaluating the characteristics of traction systems in lightning strike environments are provided through simulation, which can lay a certain technical foundation for improving the safe operation of traction power supply systems.