Abstract: Heavy-load railroad is dozens of kilometers long, with mountains along the route, a high proportion of overhead power supply lines, and high terrain of traction substations, which together lead to an increase in the probability of lightning strike failures. The railroad contact network is a single-phase effectively grounded system with a voltage level of 27.5 kV, so its insulation level is only comparable to that of the 35 kV overhead lines of the power system, with a lower level of lightning resistance, which makes it more prone to lightning faults. Since the contact network has no backup, and the train running density is large, the occurrence of lightning failure will seriously threaten the safety of railroad transportation. The rapid positioning of lightning faults can help reduce the economic losses caused by lightning strikes, and the traveling wave positioning method is widely utilized in the fault positioning of transmission lines due to its advantages of fast positioning speed, high ranging accuracy, and low input cost. However, the traditional fault current traveling wave localization method is difficult to implement in the complex electromagnetic environment of the railroad, so according to the operating characteristics of heavy railroads, the over-voltage action characteristics of the lightning arrester in the process of lightning protection are studied, the energy characteristics of the line under the occurrence of non-faulty lightning strikes and flashover faults are analyzed by using the TEO energy method, the judgement of the insulator flashover position is realized. The location of the line when lightning strikes is calculated through traveling wave analysis, and verified by PSCAD simulation software, and the error is kept within 50 m.