The invention provides a pixel driving method and device. The method comprises the steps of detecting whether a received picture to be displayed is a reloaded picture or not; if the picture to be displayed is the reloaded picture, converting the picture to be displayed into a corresponding gray scale picture according to a preset conversion rule; generating a data wire signal according to data information of the gray scale picture so as to drive each sub pixel to display the gray scale picture. The pixel driving method has the advantages that the problem that too much heating is caused since a source electrode driving chip displays the reloaded picture can be effectively avoided; meanwhile, heat radiation fins do not need to be attached on the source electrode driving chip by the method; the manufacturing efficiency of a liquid crystal display is not influenced.