Abstract: In order to solve the problem that the fault feature is not obvious when the single phase ground fault occurs in the mine power supply system, the wavelet packet method is easy to select the wrong line.this paper proposes a line selection method based on CEEMD and wavelet packet. In this method, firstly, the zero sequence current is decomposed by CEEMD, the high frequency IMF1 component obtained by decomposition is extracted and wavelet packet transform is carried out, the sum of wavelet packet energy of each frequency band is calculated and sorted, the characteristic frequency band is determined according to the principle of maximum energy and the polarity of the maximum value of wavelet packet decomposition coefficient is compared, and the line with opposite polarity is determined as the fault line. 35/6kV simulation model of mine power supply system is built by RTDS. The simulation results show that this method has better accuracy of line selection, and is less affected by different fault factors, and has higher accuracy of line selection under different fault conditions.