The invention discloses a short-term power grid frequency modulation control method and system based on an energy storage battery. The method comprises: determining a frequency offset curve accordingto an ultra-short-term load; determining a frequency offset at an arbitrary time according to the frequency offset curve; determining whether an absolute value of the frequency offset is greater thanan absolute value of a primary frequency modulation dead zone, and acquiring a first determination result; determining an energy storage charging unit adjustment power factor and an energy storage discharging unit adjustment power factor if the first determination result indicates that the absolute value of the frequency offset is greater than the absolute value of the primary frequency modulationdead zone; determining the actual output power of the energy storage battery according to the energy storage charging unit adjustment power factor and the energy storage discharging unit adjustment power factor. The invention can improve the capacity utilization of the energy storage battery and maximize energy storage economic benefits.