Abstract: Aiming at the problem of a number of small gob zones existing in Baorixile open-pit mining area, comprehensive geophysical method which took transient electromagnetic method as main and supplemented by shallow high-resolution seismic exploration was applied to find out the location of small gob zones. Furthermore, the drilling method and blasting method were employed to verify the detection results. Finally, the size and location of small gob zones in this open-pit mining area were accurately determined. The results are crucial importance in safe production of open-pit mining.