The present disclosure discloses a driving method and a driving device of a display panel. The driving method comprises: to detect the operating state of said display panel; to switch the bias current which is in said data line driving circuit according to said operating state of said display panel in order to make display brightness of said display panel be uniform. Through the above way, the present disclosure can improve the signal distortion caused by the leakage current of the gate signal on the data line, making the brightness of the display panel be uniform, improving the user's experience.