This disclosure relates to a liquid crystal TV set, and a method and apparatus for adjusting backlight driving voltage thereof, and the method for adjusting backlight driving voltage includes: comparing backlight driving current with reference driving current to obtain voltage feedback data, while a backlight source is being driven; making overvoltage adjustment to the voltage feedback data to generate overvoltage feedback data; and adjusting backlight driving voltage using the overvoltage feedback data to overvoltage-drive the backlight source by the adjusted backlight driving voltage. The liquid crystal TV set, and the method and apparatus for adjusting backlight driving voltage thereof according to this disclosure can improve the response speed of backlight in the liquid crystal TV set while the backlight source is being driven.