Abstract: For problems that existing fault line selection methods for coal mine power network had low detecting sensitivity and were easily influenced by neutral point operation mode and electric arc at grounding point, characteristics of sequence current and harmonic current of single phase grounding fault were analyzed, and conclusions were gotten including that the fundamental negative sequence current was allotted to distribution system from grounding line head, and no fundamental negative sequence current flowed through health line head. According above conclusions, a novel line selection method of single phase grounding fault was proposed which took fundamental negative sequence current as the first criteria and harmonic current as the second criteria, and reliability analysis and simulation calculation about the method were taken out. The simulation results show that there is little influence on the method by neutral point operation mode and fault type, and the method has better reliability and adaptability compared with traditional methods.