The Magnetotelluric (MT) method is widely used in the exploration of oil and gas resources. The time-lapse MT method can monitor reservoir dynamic distribution and interface changes by observing the time-lapse MT response caused by the change of underground electrical structures and interfaces. Traditional time-lapse MT methods monitoring simulation are based on isotropic theory and regular grids. However, the induced polarization (IP) effect is widely present in reservoirs, ignoring which can lead to interpretation errors and difficulties in time-lapse monitoring of reservoirs, especially for unconventional reservoirs with complex terrain and high water content in the later phases of development. First of all, in order to solve these problems, the Cole-Cole complex resistivity model is used in the vector Helmholtz equation to characterize the IP effect of the reservoir medium. Then, the vector Helmholtz equation discretized by the Galerkin finite element method with unstructured tetrahedral grids, has been implemented to a 3D time-lapse electromagnetic algorithm that considers the IP effect. Thirdly, the analytical solution of the ID model considering IP effect is used to verify the correctness of the 3D algorithm in this paper. Further, different IP parameter variations are set and analyzed to determine the characteristic responses of the reservoirs and discuss the resolution ability of the time-lapse electromagnetic monitoring. At last, a realistic reservoir model in the Fuling area is set up to analyze the time-lapse electromagnetic anomalies generated before and after the displacement of the reservoir. The results show that the significant differences in the time-lapse MT responses caused by changes in the IP parameters of the reservoir can be used to infer the time-lapse change process of the reservoir. In the process of reservoir displacement enhancement, the response difference is distinguished by the sensitivity to the boundary of the displacement swept region, where △ρ_xy^a can effectively respond to the change of the interface in the x direction, while △ρ_yx^a targets the y-direction.