Energy sharing is critical for zero-energy buildings on the community level. However, most existing works studied the energy sharing problems without considering the physical energy sharing circuit. In this paper, we provide a new perspective to explore the energy sharing among building with a specific energy sharing circuit, and then, the modeling, control, and verification of the energy sharing system are presented. The energy sharing system is modeled as a cyber-physical system, where the physical layer characterizes the physical energy sharing circuit, and the cyber layer represents the communication topology among buildings. In the control layer, an average state-of-charge (SoC) estimator is designed for energy storage systems (ESSs) of each building using the dynamic consensus protocol, and a cooperative SoC tracking law is designed to achieve the SoC balancing of ESSs. The closed-loop model of the energy sharing system is developed using the block diagram. A laboratory prototype is built to verify the effectiveness of the proposed energy sharing method. The experimental results verify that the proposed energy sharing system can achieve energy sharing among ESSs effectively and efficiently.