In an exploration study of the slope of an open-pit mine, three geophysical methods were employed: transient electromagnetic method, background noise method, and seismic reflection method. Detailed surveys were conducted on the northern, southern, and western slopes. The three methods collectively identified multiple fracture zones and water-rich areas in the roof of coal seam 5. The results revealed significant fracturing and water content in the northern and southern slopes, while the western slope remained relatively intact. Active source seismic exploration made it clear what the coal seams 5 and 6 were made of in terms of seismic wave group characteristics. This matched up with the supplementary exploration report’s information on how the mining area was spread out. The geological information on rock mass indices and fracture degrees provided in the supplementary exploration report was effectively complemented by geophysical techniques. The anomalies identified by the three methods showed substantial overlap. The study indicates that the rock mass in the mining area is predominantly soft rock, which softens and disintegrates easily when exposed to water, thereby affecting slope stability. It is recommended to optimize the drilling layout based on geophysical results to provide prerequisites for slope stability monitoring and management.