In this research, Finite Difference Time Domain (FDTD) is applied using nonuniform grids and second ordered Liao's Absorbing Boundary Condition (ABC) for simulating the electromagnetic shielding effect of Carbon Fiber Reinforced Plastic (CFRP) panels. Besides, these panels are unidirectional laminates with an an isotropic conductivity model. The presence of very small or thin structures is taken into account in this scheme through a simple way. This improves the flexibility of FDTD method. Hence, simulation results are able to give a clear and accurate view of this dynamic phenomenon. Moreover, these achieved results prove that a coated paint on the surface of the CFRP panels can improve the shielding performance effectively.