The present invention discloses a driving method for a source driver, for driving a source line of a display panel. The driving method includes the steps of: driving the source line with a first voltage or a second voltage smaller than the first voltage in a first driving cycle; driving the source line with the first voltage in a second driving cycle next to the first driving cycle when the source line is driven with the first voltage in the first driving cycle; and driving the source line with an overdrive voltage in the second driving cycle when the source line is driven with the second voltage in the first driving cycle. The first voltage is a normal high voltage of the display panel, and the overdrive voltage is greater than the normal high voltage.