“Sneak Circuit” is defined as the unexpected path or operational status in an electric or electronic circuit due to the limitation or oversight in design by human. The sneak circuit can be triggered to operate under certain conditions, which results in an unwanted or unintended action. As power converter is an artificially designed system, it is undoubted that sneak circuits exist in power converters, while sneak circuit phenomena have been proved in some typical power converters. In order to improve safety and reliability of a power electronic system, it is necessary to understand thoroughly the sneak circuit in power converters under all possible practical conditions. Thus, this paper aims at providing a brief review of sneak circuits in power converters, and summarizes the sneak circuit analysis(SCA) methods based on the graph theory. Finally, some applications on power converters by making use of the SCA principle of sneak circuit analysis are included.