Abstract: The DC power grid with multi-voltage levels can meet the requirements of voltage level in different regions to connect to various energy sources and loads, and it is the development direction of future power grid construction. Power flow analysis of DC power grid is the basis of grid planning, design and operation control. Compared with traditional power flow analysis, power flow analysis of DC power grid with multi-voltage levels is more complicated due to its flexible control methods and diverse operation modes. Taking into account the control modes of converter station, firstly, the DC power grid with multi-voltage levels is partitioned, and the steady-state equivalent model for DC power grid with multi-voltage levels is established. Then, the node admittance matrix and power flow equation are established based on Newton iterative method, and the power flow calculation method of DC power grid is derived. Finally, a multi-terminal DC grid model is built based on PSCAD, which verifies the validity and correctness of the proposed calculation method.