Abstract: In order to address the problems that arise when a single-phase ground fault occurs in the current mine grounding power supply system, this paper proposes a line selection method based on parameter optimization variational mode decomposition (VMD) combined with the thorough component of ze-ro-sequence current. These faults are caused by the difficulty of extracting signal features from the arc suppression coil and the significant influence of noise signal. In this method, the whale optimized VMD is used to decompose the zero-sequence current signal, and the fault line is identified according to multiple criteria of non-power frequency component signal energy, power frequency component signal polarity and waveform correlation. Using RTDS/RSCAD to build a mine power supply system model, simulated and tested different fault conditions, including fault grounding resistance, fault ini-tial phase angle, and fault point location of different fault lines. The results show that this method has a more intuitive line selection effect under the premise of ensuring accuracy and reliability, regard-less of the fault conditions.