A method for controlling light-emitting diode (LED) backlight modules applied in an electronic device is provided. The electronic device includes a first display and a second display. The second display includes at least two display areas. Each display area corresponds to one LED backlight module, and each display area displays option icons of an option type. The method includes: determining the file type of a file currently displayed on the first display and determining which of the option types the determined file type corresponds to; determining which of the at least two LED backlight modules the at least one determine option type corresponds to; and outputting control signals to turn on at least one of the determined LED backlight modules. A related electronic device is also provided.