Inner coal working face geologic abnormal body like fault zone, fold, coal seam thinning zone or no coal zone, collapse column, rich water zone, etc, not only directly affecedt the fast and efficient production of coal seam working face, but also related to the mine safety production. Since the successful development and application of radio wave tunnel perspective equipment and detection technology(hereinafter referred to as the pit prospecting technology), with its advantages of light equipment, high efficiency, fast data processing and analytical, high abnormal resolution ratio, was the geological structure detection means that widely used in inner working face of mine. The principle and working method of pit prospecting technology was introduced, with data processing and its limitations， which provided technical experience and reference for similar condition.