The invention discloses a scheduling method for assisting power peak shaving by using an energy storage system. The method comprises steps: power system parameters, load parameters and unit parametersof multiple units in the power system are obtained; a scheduling model with the minimum total operating cost as an objective function is built; constraints for the scheduling model are built; and a simulation platform is used to simulate and solve the scheduling model, and the output situation of the multiple units is determined as the optimal scheduling scheme. Based on the operation flexibilityand the rapid adjustment capability of a gas-fired genset, the scheduling model aiming at consideration of the total operating cost of the conventional thermal power unit operating cost, the gas-fired genes cost, the wind curtailment penalty cost and the delivery cost to be minimum is built, the energy storage demand for power peak shaving is more accurately embodied, and the economics of scheduling is enhanced. Based on the actual characteristics of the power grid, a scheduling model considering power delivery is built, a role of enhancing the system delivery ability when energy storage participates in power peak shaving is fully played, and the practical value is achieved.