The invention discloses a light source adjusting method and apparatus. The method comprises the following steps: obtaining current ambient light brightness; and adjusting the light source brightnesses of at least two keys to respective preset brightnesses according to the current ambient light brightness, to ensure that the difference of display contrasts of every two of the at least two keys is in a preset range. According to the technical scheme, as a display contrast changes with ambient light brightness, when the light source brightness of each key is adjusted according to different ambient light brightnesses to ensure that the display contrasts of the two is less, the difference of display contrasts is reduced, the brightness difference, felt by a user, of keys can be reduced, and user experience is improved.