Resistivity imaging and other resistivity methods are widely used to detect hidden troubles in embankments. Embankments have complex shapes and are made by multiple materials. Finite Element Method (FEM) and other numerical methods are efficient ways to solve the forward problems of complex objects such as embankment. This article introduces how to use ANSYS to build a 3D embankment model and simulate the detection of internal erosion. We simulated the process of detecting a seepage channel in embankments by Wenner arrays and list the simulation results and parts of the APDL source program. ANSYS and APDL are very suitable tools to rapidly solve the forward problems of complex objects, such as embankment.