In areas covered by thick loess and looses sand, 3D seismic is inefficient in detecting fault structure. In view of this situation, an engineering try by using TEM method to detect the fault structure was done in Youyu mine. The grid is 40 m × 20 m and the exploration area is 2.5 km2. The result of the area with known fault structures indicates that the fault structure where the up and down sides have electrical difference or are filled with water shows bending-down contour and electrical layer dislocation of electric layer in apparent resistivity section. The contours of fault with different drop bend in different degree, the contours bend more greatly if the drop is bigger.