The invention discloses a multi-layer composite plate. The multi-layer composite plate comprises at least four layers of one-step forming hollow insulating layers (3),wherein the upper end face of the insulating layer is composited and connected with a first glass fiber layer (1), the lower end face of the insulating layer is composited and connected with a second glass fiber layer (2), and the insulating layers are in a parallel one-step forming porous structure. The multi-layer composite plate is provided with at least four layers of one-step forming rectangular insulating layers, the insulating layer is filled with air, so that the whole composite plate is light and is high in strength, the glass fiber layers are composited on both surfaces of the hollow plate to achieve fireproofness and flame retardancy, so that the safety of the composite plate is guaranteed.