Liquid crystal display screen capable of effectively dissipating heat and backlight module thereof

The liquid crystal display screen comprises a shell, a screen is fixedly connected to one side of the shell, symmetrical mounting blocks are fixedly connected to the two sides of an inner cavity of the shell, vent holes are formed in the upper portion of the side, away from the screen, of the outer wall of the shell, cooling fins are fixedly connected to the middle of the inner cavity of the shell, and the side, away from the screen, of the outer wall of the shell is fixedly connected with the cooling fins. A turnover mechanism is arranged on the side, close to the cooling fins, of the mounting block, a driving part for driving the turnover mechanism to vertically move is arranged at the upper end of the mounting block, driven plates are elastically and slidably connected to the middle of the mounting block, and a movable plate is fixedly connected between the symmetrical driven plates. Air flow blows to the cooling fins to cool the display, when the notch of the first gear is close to the second gear, the sh