PU Sandwich panel (Polyurethane sandwiched panel )is composed of 2 layers of weather-proof colored steel sheets and jetted the hard forms of polyurethane between 2 layers which feature fireproof materials. It is suitable for the various roofs and walls referring to the large-size factory buildings, storage, exhibition halls, gymnasiums, freezing stores, purification workshops, etc, which features temp-keeping, heat insulation, weight-bearing, weatherproof with the rich colorfulness and good appearance.