Embodiments of the present disclosure relate to a method for compensating for luminance of a display panel, a display panel, and a display device. The display panel includes a display region and a non-display region, the display region and the non-display region having a boundary therebetween, the boundary passing through a pixel region and a non-pixel region of the display panel, a portion of the non-pixel region located within the display region forming a dark region within the display region, the method includes determining the luminance of the neighboring pixel adjacent to the dark region among the display pixels of the pixel region based on an area of the dark region, so as to compensate for the luminance of the dark regions with the luminance of the neighboring pixel.