Abstract: The paper proceeded from actual conditions of coal mine power grid, discussed in allusion to four cases of three-phase TA, two-phase TA, single-phase TA and zero-sequence TA. It analyzed initial travelling waves for each line of each phase current, used dual-tree complex wavelet decomposition to get relationships between amplitude and phase of modulus maxima, and then conducted ratio calculations to constitute different criterions of fault line selection or phase selection. Finally, Matlab simulation verifies reliability of fault line selection method of coal mine power grid based on dual-tree complex wavelet.