Abstract: As one of the important core devices in the power system, the transformer is prone to arc failure in its fuel tank, which may generate overpressures, resulting in a fuel tank rupture, resulting in oil leakage, explosion, or even fire in serious cases, thus poses a serious threat to the stable operation of the power system. In this paper, the internal arc fault of the transformer is reviewed from the aspects of pressure wave property, simulation model, oil arc detection method explosion-proof technology, etc. Firstly, the pressure wave property, simulation model, and pressure wave propagation law are reviewed including four pressure wave simulation models, and their advantages and disadvantages are compared. Secondly, in accordance with the characteristics of difficulty and destructive operation in the arc fault detection, the technology and the standard of arc detection in oil are summarized. In addition, key explosion-proof technology for transformer arc faults is analyzed and discussed. Finally, current challenges are analyzed according to arc fault and explosion-proof technology future development trend is forecast on this basis.