Abstract: Aiming at the safety and stability issues of the proposed substation in Pingdingshan City, Henan Province, the substation was taken as the research object. Based on the basic geological conditions and mining conditions of the substation, the goaf was detected comprehensively the transient electromagnetic method and drilling detection. By analyzing the longitudinal profile of apparent resistivity obtained by transient electromagnetic detection and the relationship curve between formation depth and apparent resistivity, it could be seen that there are low resistance anomalies in some depths. The horizontal range of the low-resistance anomaly area was further determined by analyzing the horizontal profile of apparent resistivity. The relationship between the drilling depth and the core rate obtained by drilling detection could accurately determine the depth range where the rock formation is relatively broken and has a small amount of water leakage. It could be determined that the abnormal area of the mined-out area is located in the west of the proposed area according to the comprehensive analysis of the two detection results, and there are uncertain factors in the safety and stability of the mined-out area underlying the substation, and effective mined-out area governance measures must be taken to ensure the safe and stable operation of the substation.