A firefighting method and system for energy storage, and a storage medium are provided in implementations of the present disclosure. The method includes the following. The BMS turns on a first exhaust fan corresponding to a first battery cluster where a first battery module is disposed to exhaust a preset gas from the energy-storage container, when a first gas detector disposed in the first battery module detects the preset gas. The BMS determines whether to turn on a first firefighting apparatus corresponding to the first battery cluster based on a concentration of the preset gas at each moment in a preset period and a temperature of the first battery module at each moment in the preset period, to extinguish a fire at a battery module in the energy-storage container.