The invention relates to a design of a steam dryer and particularly relates to a steam dryer used in a pressurized water reactor. The steam dryer comprises a drain pipe, a drain tank, a roof plate, a seal plate, a flowing water bed, a push plate, a cover plate, a corrugated plate, a mounting bolt and a compression bolt, wherein the roof plate, the seal plate and the flowing water bed are connected together for forming an accommodating cavity, the lower part of the accommodating cavity is connected with the drain tank, and the lower part of the drain tank is connected with the drain pipe; and a tail hook is arranged at the tail part of the corrugated plate, a water-blocking trench is further welded on the corrugated plate, the water-blocking trench is in the shape of a folded plate, and the corrugated plate is in a six-wave crest form. By adopting the steam dryer, steam in the humidity which is not more than 0.25% can be obtained after enabling the steam in the humidity of 20% to enter the dryer for separation, the dryer adopts a separation element with higher separation performance, and the corrugated plate comprises the tail hook and the water-blocking trench. The dryer is smaller in volume and high in steam-water separation performance.