A gamma voltage debugging method for an electroluminescent display device, including: turning on sub-pixels in a test region to a maximum luminance value, and recording a driving current of an electroluminescent element at this time as a maximum reference current; calculating reference current values corresponding to respective gray scales according to the maximum reference current and a preset formula; and driving the sub-pixels in the test region to emit light, and for each driving current equal to a reference current value, recording a driving voltage value corresponding to the gray scale value as a gamma voltage resulted from the debugging.