The water damage in old goaf is characterized by strong suddenness, large water gushing and destructive, which is a major hidden danger to the safe mining. Conventional transient electromagnetic detection is disturbed by external factors, and the accuracy rate is not high, while in-hole transient electromagnetic detection is mainly carried out in the borehole, with fewer disturbing factors, and the detection location is closer to the target, so the accuracy rate is higher. Roadway- hole transient electromagnetic detection technology, can make up and verify each other, and is conducive to the accurate enclosure of the old goaf.