Distributed energy storage plays an important role in suppressing the fluctuation of intermittent power supply, participating in peak shaving, improving power quality and improving power supply reliability. How to quantitatively evaluate the energy supply and regulation ability of energy storage system is very important for tapping the adjustment potential of various power and energy storage combination configurations and optimizing the allocation of distributed energy storage. In this paper, the response speed characteristics and power regulation characteristics of various energy storage systems are analyzed according to the commonly used energy storage forms and devices. Based on the analysis of various factors affecting the regulation capacity of energy storage systems, an evaluation model of regulation capacity of energy storage systems based on fuzzy comprehensive evaluation is proposed, which can be quantitatively evaluated for different energy storage combination modes and different capacity allocation ratios. Estimating the energy supply and regulation performance of distributed energy storage system provides a practical and effective method. The effectiveness of the proposed method is verified by a simulation example.