Zhangbei Demonstration Project (namely Zhangbei Project) will be the first MMC-HVDC grid in the world. Different from previous multi-terminal HVDC projects, DC circuit breakers are adopted in this project to isolate DC line faults. Four terminal ring connection of converters can provide circuitous and standby channels for power flow. This improves the flexibility and reliability of operation of the project greatly and forms the real MMC-HVDC grid. Based on the characteristics of different AC systems connecting to each converter in the Zhangbei Project, the related functions of the control system structure and coordination control for this project are studied and proposed. Corresponding control strategies with and without inter-station communication conditions are proposed. The feasibility and rationality of the control strategy are verified by closed-loop RTDS simulation. This work is supported by National Key Research and Development Program of China (No. 2016YFB0900905) and Science and Technology Project of State Grid Corporation of China (No. 5202011600TV).