The invention discloses an energy storage power station system based on multi-network integration and a transient control method. The system comprises a monitoring host, a telecontrol device, a transient controller and at least one energy storage converter. The transient controller is an embedded device for acquiring parameters of the energy storage power station at the common connection point andsending an instruction to the energy storage converters. The monitoring host, the telecontrol device, the energy storage converters and the transient controller are connected through a data network running an IEC61850 MMS protocol. The energy storage converters and the transient controller are connected through a data network running an IEC61850 goose protocol. The method is used for carrying outtransient control on the system. According to the invention, the defect that the architecture of the current energy storage power station does not have the transient response capability is solved; the energy storage power station can have the transient support capability of power grid frequency, voltage and the like; active and reactive rapid support is carried out on a transient fault of a powergrid, and the power grid accessed by energy storage is safer and more stable.