Abstract: This article introduces an accident case of a 10 kV line due to a single-phase grounding fault and voltage rise, which resulted in a decrease in the insulation performance of other line cable heads, resulting in a phase to phase short circuit. At the same time, due to the mechanical jamming of the line switch, it was unable to open normally, resulting in a skip trip. The handling process of the story is described in detail, and the cause of the fault is analyzed. Finally, corresponding corrective measures are provided.