The large-capacity, centralized grid-side lithium battery energy storage power station is of positive significance for improving the system’s flexible regulation ability and safety and stability after the access of large-scale high-proportion new energy and large-capacity DC. To further study the response of large-scale lithium battery energy storage power stations connected to the power grid, this paper proposes an equivalent simulation method of large-capacity lithium battery energy storage power stations. Firstly, the main ideas and methods in the simulation of energy storage power station are summarized from four aspects: lithium battery pack modeling, parameters design of power conversion system (PCS) and converter transformer, control strategies and equivalent modeling method. Then, an equivalent model of 100 MW lithium battery energy storage power station based on the actual design parameters of the energy storage power station is built on the PSCAD. The simulation test results show that the equivalent energy storage power station model can maintain the basic characteristics of a single energy storage unit. Its control accuracy, response time, regulation time and switching time of charge and discharge are all within the relevant national standards, which make it capable of analyzing and simulating the external characteristics of large capacity energy storage power station on the side of grid connection, and can provide a reference model for related simulation research.