The disclosure provides a display driver, applied to process image data sent by a processor, the driver includes a time sequence controller, a data receiver connected with the time sequence controller electrically, an image processing module, a data storage module, a pulse width modulation register and a source electrode driver; when the display processor sends static image data, the static image data received by the data receiver is processed by the image processing module, the pulse width modulation register stores a backlight adjustment signal generated by the image processing module first processing the static image data, the static image data processed by the image processing module is stored in the data storage module, the time sequence controller controls the source electrode driver to read the static image data stored in the data storage module, simultaneously reading the backlight adjustment signal stored in the pulse width modulation register to adjust backlight.