A universal analysis calculation method is presented for DC grid with DC power flow controllers (DCPFC). The impact of DCPFC and the control of converter station are taken into account in the algorithm. Theoretical calculations are carried out to analyze the sensitivity of DCPFC to the power flow controlling. The impact of DCPFC on power flow of DC grid is investigated. The CIGRE B4-58 DC grid test system is modeled in PSCAD/EMTDC to validate the mathematic calculations. Results show that the novel power flow calculation method is accurate.