For MMC-MTDC Transmission System, taking the requirements of the accuracy and speed of DC voltage and active power regulation in the actual project into account, a novel DC voltage coordinated control strategy is proposed in this paper. The strategy combines translating U-P droop curve and changing the slope of U-P droop curve , Improving dynamic response speed of DC network when power changes and eliminating static bias, and ensures DC voltage stability and inter-station power balance in MMC-MTDC system. Finally, a parallel-type four-terminal MTDC scheme is developed in RT-lab real-time simulator, and then steady and transient state is performed to validate the feasibility of the proposed Novel DC Voltage droop Control Strategy.