In this paper, a new foam concrete-extruded polystyrene composite wall panel (FCPW) is proposed. In order to investigate the response of these wall panels to the loading conditions that may occur during an earthquake event, a total of three specimens were designed in this study to study the seismic performance of the wall panels with different sizes of cyclic loads applied to them. By analyzing the seismic parameters such as hysteresis curve, skeleton curve, ductility and stiffness degradation factor of the wall panels, it is concluded that the wall panels have good seismic performance. Both the test phenomenon and damage mechanism indicate that shear damage is the damage form of the specimen. Comparing the specimens, it can be seen that the height-to-width ratio and the strength of the specimen itself have obvious effects on the seismic performance. The larger the height-to-width ratio is, the larger the ductility is and the better the seismic performance is. The smaller the thickness of the concrete is, the smaller the ductility is and the worse the seismic performance is. This study helps to update the iteration of composite wall panels composed of extruded plastic board and concrete and provide a reference for future research.