It can be seen that electrical resistivity imaging method, with high efficiency and multiple measuring lines, has shallow surveying depth limited by array length. The combination of arbitrary pole pitch sounding and telecontrol electrode array method placing two wires A, B and telecontrol electrode array at the ends of array can triple the conventional measurement length through data merging and inverting in the prospecting of crevasse geothermal resources in Hainan Island. It is suggested that further improvement and promotion of the method mentioned above is still needed, though it has already achieved good geological effect.