With the rapid development of distributed energy, DC load, variable frequency load and voltage sensitive load, DC microgrid will be widely used in future power grid. At present, there is no unified standard for grounding design of DC microgrid, and the grounding methods used in various demonstration projects in China are also different. In this paper, the advantages and disadvantages of various grounding methods for the DC microgrid are analyzed based on two-level voltage source converter (VSC) from the perspective of AC and DC side harmonics. It is recommended to adopt the filter capacitor neutral point grounding method of converter LCL filter on the AC side and DC capacitance neutral point grounding method on the DC side. The selection of grounding method in practical engineering needs to consider many factors, so the conclusion of this paper can not be used as the evaluation standard of DC micro-grid grounding design, but they can provide reference for designers.