A backlight control method, a backlight module and a display apparatus are disclosed. The backlight control method comprises: dividing a backlight into N blocks; determining whether each of the N blocks satisfies a high current driving start-up condition or not according to a pixel signal in each input frame of image signal and determining blocks which satisfy the high current driving start-up condition as candidate blocks; setting blocks among the candidate blocks which are determined to be driven by high current as selected blocks in a case that power consumption of each frame of picture does not exceed total backlight power consumption without dynamic backlight control; and calculating backlight driving pulse width modulation duty ratios of the selected blocks according to a correspondence between brightness and pulse width modulation duty ratios, and transmitting the calculated backlight driving pulse width modulation duty ratios to a backlight driving circuit.