This application embodiment provides a method for equalizing the battery module, an apparatus, a battery module and a power management controller, including: judging whether the first battery core and the second battery core enter their respective fully-charged interval; if the first battery core enters and the second battery core doesn't enter, discharging the first battery core until the second battery core enters; if the first battery core doesn't enter and the second battery core enters, judging whether the maximum value of the first charging voltage of each battery cell in the first battery core is greater than a third preset value; if so, discharging the second battery core until the first battery core enters; if not, controlling both to rest a preset time; after resting for the preset time, discharging the first battery core and the second battery core until the SOC of each battery cell enters a same state.