The utility model discloses a bridge floor seamless expansion and contraction device based on corrugated steel plates. The device comprises built-in steel plate parts and an expansion joint padding packing layer which is located over the built-in steel plate parts in a padded mode, the built-in steel plate parts are distributed on an expansion joint left between every two adjacent girder segments of a girder of a constructed bridge in the front-back direction, and each built-in steel plate part comprises built-in corrugated steel plate parts and a stiffening steel plate which is located below the built-in corrugated steel plate parts; bridge floor pavement structures are paved on all the girder segments of the girder of the constructed bridge, and a sliding panel is paved on a protruding segment, protruding out to the outer side of the corresponding bridge floor pavement structure, of each girder segment; each built-in corrugated steel plate part comprises a straight steel plate segment and two corrugated steel plate segments, each stiffening plate is located below the corresponding straight steel plate segment, and multiple shearing force parts are arranged on each corrugated steel plate segment. According to the bridge floor seamless expansion and contraction device, the structure is simple, the design is reasonable, the construction is convenient, the use effect is good, and the problems that existing expansion and contraction devices are inconvenient to install, poor in load-carry capability and durability and short in service life can be solved.