The invention relates to an improved master-slave control method for a DC distribution network. The invention is technically characterized in that the method comprises the following steps: Step 1, designing an adaptive droop controller with a dead zone; and 2, setting one MMC converter station as the main station with the working mode being a constant voltage control mode, and setting the other MMC converter stations as slave stations with the working mode being the control mode of the adaptive droop controller with the dead zone in the Step 1. According to the invention, seamless switching ofoperation modes can be realized and the stability of DC voltage can be ensured when communication failure occurs.