This application relates to the field of communications technologies, and provides ambient light and optical proximity detection methods, a photographing method, and a terminal, so that an entire display screen of the terminal is used to display a user interface, and this improves user experience. The method specifically includes: controlling, by a terminal, some areas of a display screen to display a black picture for a plurality of times; and when the areas display the black picture, obtaining an intensity of ambient light detected by an ambient light sensor to adjust luminance of the display screen.