For the purpose of exploring the applicability of various devices of high density resistivity method and according to the finite difference method, the authors conducted forward modeling of high and low resistance abnormal body, which included 7 kinds of devices, i.e., secondary arrangement, tertiary arrangement, Wenner device, dipole device, differential device, dipole-dipole device, and schlumberger device. The simulation results show that the effect of the dipole device for detection of low resistivity anomalous body and high resistivity anomalous body is better, the Wenner device is applicable only to the detection of high resistivity of abnormal body and the boundary between high and low abnormal bodies, and the shapes or positions of the high and low abnormal bodies detected by other devices show certain deviations from the actual situation. The simulations were applied to loess cave and karst investigation, and achieved good detection results. The results obtained by the author provide a reference for the investigation in similar work areas.