The present invention provides a buffer unit for the touch-control driving circuit of the display device, the display device comprises a display panel, which includes gate lines, common electrode lines, pixel electrodes and a common electrode, the common electrode lines are used as touch-control scanning signal lines in the touch-control driving circuit, wherein the buffer unit comprises an input terminal connected to an output of a shift register unit in a gate driving circuit and an output terminal connected to a corresponding gate line, the buffer unit is used to adjust a voltage input to the gate line to a target voltage in a touch-control phase, and a difference between the target voltage and a voltage of the pixel electrode is smaller than a first value when a high level signal is applied to the touch-control scanning signal line. The present invention further provides a touch-control driving circuit, a display device and driving method thereof. The present invention can reduce occurrence of the phenomenon in which a curve of the transconductance of the thin film transistor in the pixel unit is drifted, so that service life of the thin film transistor may be prolonged.