Provided are a multi zone backlight controlling method and a device thereof. The method includes: obtaining original grayscale values of pixels of the image; obtain a backlight control coefficient correction factor according to the original grayscale value; obtaining a first backlight control coefficient and a second backlight control coefficient based on the backlight control coefficient correction factor and the original grayscale values, and adjusting backlight brightness according to the first backlight control coefficient and the second backlight control coefficient, thereby reducing difference between the display image and the real image.