Source driver and driving method thereof

The invention discloses a source driver and a driving method thereof for a display device. The source driver comprises a receiving module which is used for receiving multiple pieces of display data, multiple transmission channels of which each contains a temporary storage module and is used for receiving one piece of the display data, a voltage level converter which is used for judging a voltage level of one piece of the display data, a polarity digital-to-analog converter which is used for carrying out digital-to-analog operation on the voltage level of one piece of the display data, and an output module which is used for outputting the multiple voltage levels of the multiple pieces of display data after completion of digital-to-analog operation, wherein the multiple pieces of display data correspondingly output by adjacent two of the multiple transmission channels contain voltage levels of different polarities, and the output module carries out an odd number of exchange operations before outputting the multiple voltage levels.