Abstract: With the wide application of small current grounding fault location devices in China's medium-voltage power distribution systems, the research on the application of different fault location methods has become increasingly significant in practice. This article studies the fault location principles of various grounding fault location methods, including the parallel connection of arc suppression coil and resistance method, high-frequency signal injection method, and zero-sequence current amplitude-phase comparison method, etc. It also analyzes and explores several new grounding fault location methods combined with intelligent algorithms. Based on this, it conducts a comparative analysis of the advantages and disadvantages of various fault location methods and their applicable scenarios, which has certain reference value for the research and application of fault location technology for small current grounding systems.