Abstract: The disclosure provides a method and system for monitoring a battery short circuit and an apparatus. The method includes: receiving collected electrical signal information of all cells in each traction battery; performing self-discharge observation and calculating a self-discharge rate based on a cell voltage in electrical signal information of each cell after depolarization is completed, to determine whether there is an internal short circuit in a traction battery where the cell corresponding to the self-discharge rate is located; and triggering alarm handling for the internal short circuit in the traction battery based on a back-fed result that there is an internal short circuit in the traction battery.