Abstract: The side leading prospecting technique in underground working face is one of new underground galvanic resistivity prospecting techniques. This paper expatiates on the technique’s basic principle and its application to exploring collapse column in coal working face.The results indicate that the technique can prospect the position and the rich water characters of the bearing water and conducting water of collapse column, can prevent the accident of the break out water or mine flooding, and play an important guiding role in controling the underground water in mine.