Composite energy storage is more effective than single energy storage in stabilizing new energy’s fluctuation and is widely used in the micro-grid. Its capacity allocation strategy is directly related to power supply’s reliability. This paper proposes a study on the optimal allocation of composite energy storage for integrated energy stations in low-carbon parks. Based on the calculation of the battery’s storage capacity and super-capacitor in the integrated energy station of a low-carbon park, the optimization model of composite energy storage capacity is constructed with the power dispatching strategy as the optimization objective. The analysis results of the actual example show that the active power loss of the integrated energy station is reduced by 1. 7 MW after the configuration of the composite energy storage is optimized by this method. The optimization effect is good, which has important value for improving the energy utilization rate of the micro-grid.