The invention discloses an energy storage equipment power balance control method and system. PCS equipment with a V/F function is arranged in a photovoltaic power station, a wind power plant, an energy storage station and a wind power-photovoltaic energy storage hybrid power station, so that a power grid established by the PCS equipment with the V/F function can be firm and reliable, and stable operation of load equipment under certain power can be met. By carrying out balance control on the power of the energy storage equipment, the method is suitable for the wind power plant, a photovoltaicfield, the independent energy storage power station, the wind power-photovoltaic energy storage hybrid power station and a power plant with V/F mode PCS equipment, and is wide in application range; power output is flexibly adjusted according to load conditions, and stability and reliability of the power grid are guaranteed; the PCS equipment with the V/F function can be ensured to have the maximumpower output capability, and the maximum load capability of the power grid is maintained.