Abstract: The present invention provides a display device and a brightness adjustment method of the display device. The display device includes a light-emitting surface, the display device includes a camera area and a display area, a display panel, and a light transmittance adjustment layer disposed on a side of the display panel close to the light-emitting surface. The light transmittance adjustment layer includes a first adjustment area corresponding to the camera area and a second adjustment area corresponding to the display area. In the present invention, a light transmittance of the first adjustment area and/or a light transmittance of the second adjustment area of the light transmittance adjustment layer is/are adjusted, so that a brightness of different areas of the light-emitting surface is kept uniformity.