The invention discloses a GOA unit, a driving method thereof, a GOA circuit and a display device, wherein the GOA unit, the driving method thereof, the GOA circuit and the display device belongs to the field of display technology. The GOA unit comprises a buffer module, a pull-up module, a pull-down module, a keeping module, a charging module and a discharging module. In a buffer period, the discharging module is controlled by a first voltage which is input from a first clock signal end and writes a second voltage that is input from a power supply signal end into an output signal end. In a pull-down keeping period, under controlling of voltage which is input from a second clock signal end, the keeping module writes the first voltage which is input from the second clock signal end into a pull-down node; and under controlling of voltage of a pull-down node, the discharging module writes the voltage of the power supply signal end into an output signal end. Therefore the first clock signal end and the second clock signal end respectively make the discharging module perform discharging on the output signal end. The GOA unit, the driving method thereof, the GOA circuit and the display device settle a problem of relatively low noise reduction effect of the GOA unit in prior art and improving noise reduction effect of the GOA unit. The GOA unit, the driving method thereof, the GOA circuit and the display device are used for GOA noise reduction.