As a distributed energy storage with high flexibility, high reliability, and a green economy, the energy storage system with phase change materials can provide flexible and reliable auxiliary services for the grid as a kind of adjustable load. For the purpose of further investigating the application potential of distributed energy storage systems with phase change material, a kind of regional-joint peak-load shifting strategy is presented based on the aggregated system with shared phase change energy storage. Firstly, an aggregated controllable model for units of distributed phase change material energy storage is proposed. After that, a feasible regional-joint control architecture based on shared phase change energy storage is designed. Then, a joint peak-load shifting strategy of intra-regional and inter-regional joint peak-shaving and valley-filling control strategies is established under different business models such as the non-cooperative game and the cooperative game. Finally, the proposed control strategy is effectively solved by the quantum particle swarm algorithm. The simulation results verify the feasibility and effectiveness of the proposed joint peak-shaving strategy in reducing the load variance and regional economic cost. The proposed method is also a new approach to grid auxiliary service.