A display panel (20), a display device and a debugging method thereof are provided. The display panel (20) includes: a base substrate (1), including a display region (A) and a non-display region (B) surrounding the display region (A), the non-display region (B) including a binding region (C) located on one side of the display region (A); and a plurality of sub-pixels (2), located in the display region (A). Areas of pixel aperture regions of the plurality of sub-pixels (2) tend to increase in a direction from the binding region (C) to the display region (A).