In the paper, the protective equipments of the bridges were studied. The new type of protective devices, which was the rectangular column sandwich plate protective devices, and they were suggested. The ANSYS/LS-DYNA, which is non-linear dynamics finite element software, was applied to simulate the crashworthiness performance of the rectangular column steel sandwich plate, and analyzed the crashworthiness performance factors of the sandwich plate from the different structure parameters to optimize the overall crashworthiness sandwich plate. After structural optimization, it can be gotten that the rectangular column sandwich plates were better than traditional steel plates in crashworthiness performance. Then, the sandwich plate was used to replace the outside steel plates of the traditional box-protective device, from that obtained the overall crashworthiness performance of the rectangular column steel sandwich protective devices were better than the traditional box-protective device.