Abstract: Transformer is one of the most important devices in a power transmission system. The pressure rise caused by arc faults in the transformer oil tank can easily lead to tank explosion and even combustion, causing large-scale fire accidents and posing a serious threat to the safe operation of the power system. In this paper, the development of transformer fault warning technology is summarized from the aspects of transformer status monitor and evaluation, the strategy for quickly clearing transformer arc faults is introduced, and the development of transformer explosion-proof technology is elaborated from the aspects of transformer arc fault pressure characteristics research, transformer oil tank optimization design, and pressure release technology. Transformer fire protection technology is also briefly introduced. Based on summarizing the research on transformer arc fault explosion, this paper proposes a comprehensive transformer arc fault explosion defense system at four levels: fault warning, elimination, explosion prevention, and fire protection. This paper provides a complete idea for the development of transformer explosion-proof technology and for ensuring the safe and reliable operation of the power transmission system.