Provided is a method for determining a light-leakage degree of a display panel, applicable to a light-leakage detecting device, wherein a display region of the display panel comprises a plurality of sub-regions, and the method includes: acquiring a brightness value of each of the sub-regions when a target color is displayed in the display region; and determining, in response to detecting that the plurality of sub-regions comprise at least one light-leakage sub-region, the light-leakage degree of the display panel based on an average of brightness values of the plurality of sub-regions and a brightness value of the light-leakage sub-region.