Abstract: This article focuses on a large-scale factory fire accident that occurred during typhoon weather. In the early investigation process, the site of the fire was uncertain, the ignition source was unknown, physical evidence could not be extracted, and the cause of the fire could not be determined. By retrieving multi-dimensional electronic data related to the fire site and the cause, such as video data, network data, electricity meter data, and high-voltage recording data, combined with the mechanism and triggering factors of the formation of high-voltage power supply fault traces, comprehensively analyzed and identified the cause of the fire. The investigation can provide reference for the investigation of related types of fire accidents.

Key words: drop type fuse, high voltage power supply, recording data, fire site traces, fire investigation