Backlight adjusting method and device

The invention provides a backlight adjusting method and device. The backlight adjusting method includes the steps that an overall reinforcement coefficient is selected according to the color component value of part of or all pixels on an image or fixed in an initialization manner, the overall reinforcement coefficient is used for reinforcing the image, a new backlight brightness corresponding to the overall reinforcement coefficient corresponding to the color component value is calculated according to the corresponding modulation relation among the display intensity, the backlight brightness and the color component value, and backlight of a display device is adjusted according to the backlight brightness obtained through calculation. By means of the reinforcement processing on the image, the problems that in the backlight adjusting process, a highlight area exists on the image, details disappear and part of pixels are fuzzy are resolved, the backlight is adjusted through the backlight brightness corresponding to the worked-out overall reinforcement coefficient, and accordingly the backlight brightness can be reduced as much as possible on the premise of not affecting the sense experience of users, and the purpose of reducing power dissipation is achieved.