The present invention provides a device and a method for adjusting Gamma voltage. The device for adjusting Gamma voltage comprises a Gamma voltage generating unit used for generating a plurality of Gamma voltages, the Gamma voltage generating unit comprising a plurality of output terminals for outputting the plurality of Gamma voltages; and a plurality of output units, output terminals of each of which are connected to output terminals of a corresponding Gamma voltage generating circuit among a plurality of Gamma voltage generating circuits of the display panel to be adjusted in one-to-one correspondence, the plurality of output units being used for outputting the plurality of Gamma voltages to output terminals of the Gamma voltage generating circuits.