A method for controlling a power battery is provided. The method includes: detecting a maximum temperature and a minimum temperature of the plurality of single cells, a plurality of first temperatures of positive electrodes and/or a plurality of second temperatures of negative electrodes, and a plurality of third temperatures of cores; determining whether the plurality of first temperatures and/or the plurality of second temperatures are within a first temperature range; determining whether the plurality of third temperatures are within a second temperature range; managing the power battery; and determining that a connection failure occurs in the power battery if one of the plurality of first temperatures and/or one of the plurality of second temperatures is not within the first temperature range; and determining a core related failure if the third temperature of a first single cell is not within the second temperature range. Further, a system for controlling a power battery is provided.