Rotatable sleeping berth on upper layer of truck

A rotatable sleeping berth on the upper layer of a truck comprises a sleeping berth body, and a front outer wrapping piece and a rear outer wrapping piece are arranged on the two side edges of the sleeping berth body in the length direction respectively. One side of a rear outer wrapping piece of the sleeping berth is connected with a hinge device through a connecting piece, the hinge device fixesone side of the rear outer wrapping piece of the sleeping berth to the rear wall of the carriage, and a winding device is arranged on one side of a front outer wrapping piece of the sleeping berth. Asupport fixed on a roof is used as a fulcrum; the safety belt is used for assisting in supporting the outer end of the upper-layer sleeping berth; the inner end of the safety belt is fixed on the rear wall of a carriage through a hinge, and the sleeping berth can rotate by taking the end where the hinge is located as a fixed point through stretching of the safety belt, so that the upper sleepingberth can rotate by a certa