Abstract: In order to solve the present zero sequence current direction protection of the mine high voltage distribution box could not handle different small groundi ng current system, which could cause inconvenient problems to the production and application, according to the phase relationship between the zero sequence current component and the zero sequence voltage of the earth leakage branching-off in each small grounding current system, a zero sequence current component specific ampl itude and specific phase selectivity leakage protection system of the mine high voltage distribution box was provided.With different algorithms set on the different groun ding system of the software, each small mine grounding current system could be applied.The lab experiments showed that under the single phase fault status, the syste m could be accurate and reliable to detect the fault line and to drive the trip.