Backlight brightness control method, backlight brightness control device and display terminal

The invention provides a backlight brightness control method, a backlight brightness control device and a display terminal. The backlight brightness control method provided by the invention includes the following steps that: brightness information of pixel points of a current image is acquired; the global brightness information of the image and the regional brightness information of subregions of the image are acquired respectively; the backlight brightness control value of each subregion is obtained according to the global brightness information and the regional brightness information of each subregion; and the backlight brightness of the image is controlled according to the backlight brightness control value of each subregion. With the backlight brightness control method, the backlight brightness control device and the display terminal of the invention adopted, the backlight brightness of the current image can be dynamically adjusted according to the global brightness information of the image and the regional brightness information of each subregion of the image, and therefore, high dynamic contrast and color saturation can be realized, and at the same time, phenomena of image flicker and uneven brightness when low gray-scale images appear can be avoided.