The stability of DC microgrid is one of the key topics in the field of microgrid research in recent years.In this paper,the Lyapunov method is proposed to analyze the stability of the system for the nonlinear characteristics of DC microgrid.Firstly,the development background of DC microgrid is introduced and the other research results are analyzed.Secondly,the control and physical model of DC microgrid are established, and the state space equation is given to characterize the nonlinear DC microgrid.On this basis,The stability of the system is proved by the direct method,and the stability of the system is determined by the proof process.Finally, the DC microgrid model is built in MATLAB/Simulink.The simulation results are in good agreement with the theoretical analysis at the equilibrium point,which proves the validity and correctness of the proposed Lyapunov method in the stability analysis of the DC microgrid.