The invention relates to the technical field of display screens, in particular to a liquid crystal display screen. The liquid crystal display screen comprises a wall body, a protection box, locking mechanisms, supporting mechanisms, traction mechanisms, a heat dissipation mechanism and limiting rings. The display screen can be rotated to be in a vertical state, maintenance personnel can conveniently disassemble and maintain the back of the display screen without disassembling the whole display screen, after maintenance is completed, the display screen can automatically rotate upwards for resetting under the drive of torsion springs, and the operation is convenient and quick with high climbing; the locking mechanisms can further lock and limit the horizontal and vertical states of the display screen, so that the operation of workers is more convenient, and the stability of mounting the display screen is improved; a design of air exhausting at the two sides is adopted for the protectionbox, air flow can be prevented from being blocked by a wall surface, the heat dissipation effect is ensured, an air exhaust passage of an S-shaped structure can also reduce the entry of external dust,so that the interior of the protection box is cleaner and has little accumulated dust.