The invention belongs to the technical field of composite materials, and in particular relates to a high-hardness composite material. From top to bottom, the composite material sequentially includes a first polycarbonate layer, a polymethyl methacrylate layer and a second polycarbonate layer. The upper surface of the polycarbonate layer is printed with a nano-transparent film; its preparation method is: in the first step, in a multi-slit coating device, melted polycarbonate, melted polymethyl methacrylate and melted Polycarbonate is injected into the cooling roller from three adjacent slits at the same time, so that the three molten layers are solidified and formed at one time to obtain the main material; in the second step, the nano transparent film is printed on one of the main material by the roller On the surface. Compared with the existing technology, phenol has the following advantages through the ingenious compounding of PMMA and PC and the use of ingenious production technology: light, high transparency, high light transmittance, high hardness, high transmittance, and suitable haze , Suitable softness, no bending, no cracking.