Abstract: Transmission lines have been operating in the wild natural environment for a long time, facing challenges such as lightning strikes, bird damage, insulator pollution flashover, external damage, mountain fires, and ice disasters. Timely identification of the fault point and cause after a transmission line fault can effectively prevent the escalation and recurrence of the fault. This article studies the oscillograms of several common typical faults on transmission lines, analyzes the changes in voltage and current throughout the entire process of the fault, identifies certain patterns, and summarizes them, providing important references for timely identification of transmission line fault points and causes in the next step.