Waterproof structure at expansion joint position of basement outer wall and construction method of waterproof structure

The invention discloses a waterproof structure for a basement outer wall expansion joint position and a construction method thereof, and the waterproof structure comprises a first water stop belt which is arranged in the middle of an expansion joint of a basement outer wall; the filling plate is embedded in the expansion joint; the water swelling sealing strips are embedded in the two containing grooves in the bottom of the filling plate; the grouting pipe is buried in the basement outer wall below the expansion joint, one end of the grouting pipe extends into the expansion joint between the two containing grooves, and the other end of the grouting pipe extends to the inner side of the basement outer wall; the plugging rod is embedded in an inner seam opening of the expansion joint, and the inner seam opening is filled with sealant; the flow guide plate is attached to the inner side of the basement outer wall, a water collecting groove is formed in the inner side of the flow guide plate, and a groove opening