Abstract: A hospital bed that changes bed sheets without moving the patient. It is composed of a bedstead (including a headboard, a footboard and a bed frame), a deformable bed top, a spool rack and roller shafts on both sides; the ends of the deformable bed top are fixed on the headboard and footboard respectively, and the bed top is pressed into between the roller axles by the spool rack which forms a tightened and leveled bed top that is sunken in the spool rack. Two bed sheets cover the bed, extending respectively from headboard and footboard into the spool rack and rolling on a roller axle. The roller axles and roller shafts are parallel to the cross section of the bed, and are movable between the headboard and footboard with the spool rack. When the spool rack is moving, one bed sheet is spread, another one is rolled up automatically.