The invention discloses a display control method of a liquid crystal display device. The display control method comprises steps that the brightness of the backlight module of the liquid crystal display device is acquired; whether the brightness of the backlight module is greater than a first set value is determined; the brightness of the backlight module is greater than the first set value, the display parameters of the liquid crystal display device are maintained; when the brightness of the backlight module is smaller than or equal to the first set value, the brightness of the backlight module is adjusted to the first set value, and according to the brightness adjusting value of the backlight module, the Gamma value of the display panel of the liquid crystal display device is adjusted, and display brightness of a display panel remains unchanged. The invention also provides the display control system of the liquid crystal display device.