Assembled multi-level filter-guide back-pressure piping treatment device and method

The invention relates to the technical field of equipment for flood control and rescue and relief work, and discloses an assembled multi-level filter-guide back-pressure piping treatment device and a method. The device comprises a device shell frame structure (1), multi-level filter bars (2), upper pressure plates (3) and a device cover plate (4). A plurality of regular prismatic hollow cavity structures are arranged in the device shell frame structure, the multi-level filter bars (2) are arranged in each regular prismatic hollow cavity structure, and the multi-level filter bars (2) at the bottom of the regular prismatic hollow cavity structures correspond to water inlet holes which are arranged on a grating-shaped bottom plate (7) at the bottom of the device shell frame structure. The upper pressure plates (3) are arranged above the regular prismatic hollow cavity structures, and the lateral side between each upper pressure plate (3) and the cover plate (4) at the top of the device shell frame structure is p