The voltage control strategy of DC distribution network is analyzed and a new integrated control strategy is proposed.Primary voltage regulation responses to power fluctuations on-line and quickly by DC voltage droop control.The voltage reference value and the power reference value are calculated by the power flow optimization algorithm of the secondary voltage regulation when the total DC voltage offset is the least,and the corresponding reference of the droop controller which is involved in secondary voltage regulation is periodically updated,eliminating and reducing the voltage deviation caused by primary voltage regulation, preventing the occurrence of overvoltage when large power fluctuation occurs in DC distribution network.Finally,a four-terminal structure of DC distribution network simulation model is established on Matlab/Simulink.The simulation results validate the effectiveness of the proposed control method.