Abstract: In a DC microgrid, during disturbances, the power tracking control of the converters on photovoltaic module and wind turbine side and the constant power control of the converters on the load side both present the negative impedance characteristics, increasing the risk of system oscillation instability. Firstly, a small disturbance linearized state equation of islanding DC microgrid with constant power load is deduced, and the influence mechanism of oscillation voltage and current of energy storage converter as adjustable control parameters on the system oscillation characteristics of DC power grid is theoretically analyzed. Secondly, by taking DC voltage and current as state feedback variables, a duty cycle feedback link for droop control of the energy storage converter is designed, and the control strategy of damping DC microgrid oscillation is proposed. In addition, the optimal design of parameters is realized by pole placement. Finally, through root locus and simulation analysis, it is verified that the proposed control strategy has significant damping capacity for DC microgrid oscillation, thus improving the dynamic stability of the system.