Abstract: A new type of line selection method of single-phase grounding leakage fault of coal mine high-voltage grid uses fault diagnosis method of current harmonic, zero-sequence active power method and transient zero-sequence current mutual product sum method to set membership functions of fault measures and weight coefficient, uses fuzzy theory to fusion the above functions of the three methods to calculate fault measures of line under line selection method with multi criteria, so as to judge line of single-phase grounding leakage fault. The Matlab/Simulink simulation result validates correctness of the line selection method.