Abstract: Numerical simulation is an important part of data processing and inversion interpretation.In order to improve the efficiency and the accuracy of electromagnetic wave imaging technology in engineering survey,it is important to understand the propagation characteristics of electromagnetic waves by forward modeling.In this study,the finite-difference time-domain FDTD (2,4) was used to simulate the numerical imaging of electromagnetic waves in three kinds of geoelectric models,i.e.,karst caves,faults and boulders.The multi-offset mode was used to acquire the electromagnetic wave gathers.Based on the analysis of the electromagnetic wave wavefield and the waveform profile,the authors summarized the propagation law of electromagnetic waves in different geological bodies and provided reliable basis for practical engineering investigation.The experimental results show that FDTD (2,4) can simulate the numerical imaging of electromagnetic waves in complex media with high accuracy,and also prove that the multi-offset acquisition mode has high efficiency and flexibility.