Abstract: Starting from Maxwell's equations,and using ground penetrating radar technology and Yee's spatial grid model theory of time domain finite difference method,studies on the response characteristics of different physical anomalies of the abnormal body such as empty,metal,and water-bearing stratum it respectively.Matlab being used to program,the numerical simulation is comparing different physical response characteristics of the abnormal body.At the same time,the physical simulation and field measurement experiments have been carried on,the results and numerical simulation are identical with each other.The results provide a theoretical basis for the detection of different physical anomalies.