When the reliable energy DC microgrid is connected to or cut off from the utility grid, there will remain an impulse current or voltage to both the microgrid and the utility grid. This paper proposes a flexible control method for reducing the impulse voltage and current while the DC microgrid is connected or cut off from the utility grid. Different control strategies are applied for different situations (divided as connect in and cut off). The main control method has been detailed introduced and the simulation has been carried out in MATLAB/SIMULINK environment, the control efficiency has been successfully verified through the simulation results.