A display apparatus and a method for controlling a backlight module thereof are provided. The display apparatus includes the backlight module, an input unit and a processing unit. A light-emitting device of the backlight module includes a first light-emitting unit and a second light-emitting unit. A photoelectric conversion efficiency of the first light-emitting unit is higher than that of the second light-emitting unit, and a covering color gamut of the second light-emitting unit is larger than that of the first light-emitting unit. The input unit generates an input signal. The processing unit is coupled to the input unit and configured to receive the input signal generated by the input unit, and the processing unit is coupled to the backlight module, and dynamically adjusts respective light intensity ratios of the first light-emitting unit and the second light-emitting unit according to the received input signal.