Embodiments of the present disclosure provide a method for detecting light leakage of a screen, a method for detecting ambient light, and an apparatus for detecting ambient light. The method for detecting light leakage of a screen includes: acquiring a brightness value of the screen and grayscale values of pixel points within a preset display region of the screen; clustering the pixel points based on a plurality of preset grayscale value intervals and the grayscale values of the pixel points, to obtain a plurality of pixel point sets; obtaining light leakage values corresponding to the pixel point sets based on the brightness value and fused grayscale values corresponding to the pixel point sets; and obtaining a light leakage value of the screen based on the light leakage values corresponding to the pixel point sets.