Compared with traditional AC grid, VSC-DC grid has strong advantages and has attracted great attention in the applications of renewable energy and other multi-energy access. To avoid the contention of voltage control among units of multi-terminal VSC-DC grid, this paper proposes a common DC voltage coordinated control method for multi-terminal VSC-DC grid. The proposed method uses the common DC voltage of multi-terminal VSC-DC grid as the public information source, based on different operational conditions of load units, renewable energy units, energy storage units and auxiliary power supply units, the common DC voltage of multi-terminal VSC-DC grid is controlled within the desired regions by renewable energy units, energy storage units and auxiliary power supply units respectively, then the voltage stability of the multi-terminal VSC-DC grid is well maintained. Finally, the simulation results by Saber software verify that the proposed control method can effectively control the common DC voltage of multi-terminal VSC-DC grid and maintain the balance of the system power.