Abstract: The invention provides a parameters tuning method of energy storage system and the energy storage system, and the method comprises the following steps: using PID control module to construct a closed-loop control subsystem of energy dispatching; acquiring PID initial parameters according to the energy dispatching model of the energy storage system; setting an adaptive model in the PID control module, and processing the PID initial parameters through the adaptive model to obtain PID adjusted and modified parameters; using the PID adjusted and modified parameters to modify the PID parameters and get the PID tuning parameters. What's more, the system comprises a battery module, a bidirectional converter device, an energy dispatching subsystem and a closed-loop control subsystem; and the closed-loop control subsystem is provided with a PID control module, and the PID control module is provided with an adaptive model for realizing the parameters tuning method of the energy storage system.