Carboniferous Benxi Formation is very thick in the depression of Ordovician weathering crust. Such an environment is favorable for the formation of bauxite and hence seems to be a bauxite promising area. With a successful case study of the highdensity resistivity method in a certain mining area，this paper expounds the effectiveness of the highdensity resistivity method in detecting ancient karst basins and indirect prospecting for bauxite deposits.