The invention provides a display panel and a common
voltage adjusting method thereof, and the method can firstly judge whether a display picture is a
bright spot judgment picture or a normal display picture, and then carries out the picture display through employing a smaller first common
voltage when the
bright spot judgment picture is displayed at a low gray scale, thereby preventing pixels which are dark spots from being displayed as bright spots by mistake, and improving the display quality. Therefore, dark spots can be accurately detected, and the
bright spot reject ratio is reduced; when the image is normally displayed, the larger second common
voltage is used for displaying the image, the pixel leakage current in the field blanking stage can be reduced, the image brightness under the
low frequency can be improved, and therefore the image flickering problem during high and
low frequency switching is solved. According to the invention, the first common voltage and the second common voltage which are different in size are set, the problem of picture
flicker during high and
low frequency switching can be improved by adopting the larger second common voltage when a picture is normally displayed, and meanwhile, the problem that the defect rate of bright spots is increased is avoided by adopting the smaller first common voltage when the picture is judged by the bright spots.