After a short-circuit fault occurs on the DC side of a flexible DC grid, the fault current quickly reaches a large peak, which can endanger the safe operation of the electrical equipment throughout the system. To limit the influence of fault currents within a short period after the fault, a current-suppression strategy without using additional devices is proposed. First, the structure of the DC grid and the law of rising of the current during the initial fault stage are analyzed. Then, based on the obtained law, a composite current suppression strategy including two links is proposed, the principle of selecting current-suppression parameters is given, and the development law of short-circuit current with the suppression strategy is analyzed. Finally, a four-terminal flexible DC grid model is built on the PSCAD/EMTDC platform for simulation verification. The results show that the proposed current suppression strategy can effectively decrease the overcurrent multiple of the DC line, reduce the probability of converter blocking, and achieve better current balance in the recovery phase after fault removal.