The invention relates to an energy storage capacity configuration method and an energy storage capacity configuration system satisfying frequency modulation requirements. The energy storage capacity configuration method is characterized in that: energy storage capacity parameters participated by an energy storage device and satisfying a primary frequency modulation requirement of a power system are obtained from an instruction of the power system; an energy storage capacity satisfying the primary frequency modulation requirement of the power system is calculated according to the energy storagecapacity parameters satisfying the primary frequency modulation requirement of the power system; an energy storage capacity satisfying a secondary frequency modulation requirement of the power systemis calculated on the basis of the energy storage capacity satisfying the primary frequency modulation requirement; an energy storage capacity satisfying a frequency modulation requirement of the power system is calculated on the basis of the energy storage capacity satisfying the primary frequency modulation requirement and the energy storage capacity satisfying the secondary frequency modulationrequirement of the power system; and the energy storage capacity satisfying the frequency modulation requirement of the power system comprises a technical minimum capacity satisfying different frequency modulation requirements of the power system. According to the energy storage capacity configuration method and the energy storage capacity configuration system, configuration of the energy storagecapacities satisfying the primary frequency modulation requirement and the secondary frequency modulation requirement of the power system in a power grid at present is carried out, and the technicalminimum capacity satisfying different frequency modulation requirements of the power system is obtained, thereby reducing the control defect of inadequate frequency modulation capability of the systemat present, and improving the frequency stability in operation of the power system.