The overburden failure causes the changes of the constant electric field,and the resistivity is the main parameter in these changes.2D finite element method (FEM) is used to simulate the resistivity distribution of overburden by building the mathematics models of the overburden electrical parameter changes.The calculation indicates that the resistivity varies with the electrical character of the rock in cracked zone and caving zone caused by overburden failure,and the resistivity method used in monitoring the overburden failure is practical in principle.