Abstract: A large number of untreated goafs have been left due to historical iron ore mining activities in Eastern Hebei, posing great potential safety risks. Due to considerable topographic relief and large buried depth, traditional electrical prospecting faces numerous difficulties. To clarify the distribution pattern of medium-deep goafs in an iron mine, the transient electromagnetic method (TEM) is adopted for exploration in this study. The results show that this method effectively overcomes the depth limitation of the high-density electrical method and false anomalies caused by topographic relief, and can accurately identify the spatial distribution of medium-deep goafs. Subsequent drilling verification has proven that this method has remarkable effects in detecting iron mine goafs, providing valuable references for the exploration of goafs at similar depths in future projects.