A method and apparatus for detecting a display screen are provided. The apparatus comprises: a detection module for detecting components of a primary color in the light at a display side when a first and second display signal are input to the display screen, wherein the first and second display signal are used for displaying a monochromatic image in black and a monochromatic image in a color other than black; and a data processing unit for calculating a difference between components of the primary color which are detected when the first and second display signal are input, and determining whether there is a fault in the display screen according to the difference. The effect of ambient light on detection results can be reduced, and the detection results are more close to the actual case.