DC micro-grid gets rid of considering factors such as frequency and phase , and the topology is simple and easy to control. But based on a large number of power electronic converter interfaces, the inertia of the DC microgrid is low, which will affect the safe and stable operation of the micro-grid in severe cases. In response to this problem, this paper proposes an adaptive control strategy of inertia damping with additional dynamic adjustment coefficient by analyzing the inertia requirements of the system at various stages of voltage fluctuations and the influence of inertia damping parameters on the system inertia, which can adjust the system inertia flexibly according to the voltage change rate and voltage deviation to reduce the influence of power fluctuations on the bus voltage. The small-signal model of the system is established, and the small signal stability of inertia damping parameters is analyzed by the impedance ratio criterion. Finally, the PSCAD/EMTDC simulation software is used to establish a DC micro-grid simulation model for analysis and verify the effectiveness of the proposed control strategy.