Abstract: Against high-voltage transmission tree-line failure, there is relatively little research on residual traces analysis technology. This article built a 10 kV distribution network platform and conducted tree-line fault simulation experiments in combination with outdoor soil environment, obtaining experimental samples of transmi- ssion line and conducting research on forest electrical typical traces analysis technology based on macroscopic/microscopic morphology, Micro CT, and metallographic. The research has shown that tree-line failure in 10 kV transmission lines occur under high voltage and low current conditions, with characteristics such as small melting range, difficult observation of melting transition zone, and susceptibility of conductor surfaces to inorganic burning and invasion from trees. The residual trace morphology of transmission lines at the fault contact points of trees at different positions is closely related to the leakage current during the fault process. As the severity of the fault changes, the microscopic morphology trace characteristics transform from fence like and fish scale like to honeycomb like. Different analysis methods can provide theoretical and experimental basis for the identification and analysis of forest electrical fires caused by tree-line failures from different perspectives.

Key words: forest fire, tree-line failure, traces analysis, fire evidence identification