Abstract: A thermal management system for an energy storage battery pack includes energy storage battery packs and temperature control sub-units. Each energy storage battery pack includes battery modules and a main housing used for accommodating the battery modules; the temperature control sub-units are mounted on the energy storage battery packs, respectively; each temperature control sub-unit includes a speed regulation fan used for dissipating heat for the energy storage battery pack, a temperature detector used for sensing a temperature of the battery modules and a pulse width modulation (PWM) controller; the speed regulation fan, the temperature detector and the PWM controller of one of the temperature control sub-units are in signal connection, the PWM controller is used for adjusting the duty ratio of the speed regulation fan according to the difference value between the temperature of the battery modules and a temperature threshold; and the temperature threshold is a preset value.