The invention discloses a rotatable mechanism of a box body cover plate. The rotatable mechanism of the box body cover plate comprises a box body and a box cover. The box body and the box cover are arranged on a multi-media platform, wherein two sides of an edge of the box cover are hinged on a hinged shaft of the box body through connecting components, one of the connecting components is a toothed plate and matched with a gear arranged on the box body, and the other connecting component is provided with a lock catch and matched with a limiting device which is arranged on the multi-media platform or on the box body. A torsional spring is arranged on the section, between the box body and the box cover, of the hinged shaft. By the adoption of the rotatable mechanism, the opening and closing of the box cover can be controlled by the limiting device, the box cover can achieve the automatic opening through the toothed plate being matched with the gear which is arrange on the box body under the action of the torsional spring, and the arrangement of a damping gear enables the box cover to keep a
slow speed and noiseless when the box cover opens.