A easy lap hollow steel plate structure, fastened to an elongated steel plate into an empty plate elongated plate-shaped end surface, between the upper and lower face plate having a plurality of spaced ribs of the intermediate plate forming a plurality of hollow groove, which respectively, with two sides of combining means may correspond to fit together, and the lower plate hollow board down and then extended a second hollow plate, hollow serve through the second plate formed retracted or protruding front end faces Nobuyuki techniques provide different front and rear steel plates are overlapping effect.