The audio magnetotelluric sounding method (AMT) is widely used in the highway and railway tunnel exploration to prevent geohazards during the drilling process. Most of the recent survey results show that this method has the capability of locating faults and shatter belts for which the engineering geological survey shows much concern. However, the abnormity is in low resolution and it is very difficult to determine characteristics of the dip of the fault or even to detect whether the fault is normal or reverse. The authors designed two typical comparable fault models for modeling the AMT data and used the synthetic data to do 1D and 2D inversion. A detailed comparison demonstrates that TM data show good results for characteristics of the layer while TE data give more information concerning the target orientation. The research mode used in this paper has certain reference significance for this kind of applications under complicated geological and geophysical conditions.