Complete grounding grid for safety and reliable operation of power system plays an important role.Experimental substation construction site on a hill

due to the sliding of the slope

on the north side of both upstream and downstream retaining walls had cracks. Non-destructive test on up and down slope of substation and bridleways is carried out using transient electromagnetic（ TEM） instrument

through analysis on apparent resistivity imaging map

reflects the structure of grounding grid state of experimental locations. TEM method can be efficiently and easily used in non-destructive test of grounding grid.