Abstract: DC circuit breaker（DCCB） is the key equipment to ensure the safe and stable operation of DC power grid. For the existing DCCB, the cost is too high due to the large number of devices in operation, large current during short-circuit faults, and too much energy absorbed by the arrester. A power electronic multi-port HVDC circuit breaker（MP-DCCB） with current limiting is proposed. The performance of DCCB is studied by improving its topology. The working principle and fault breaking process of the new topology are analyzed theoretically. The relevant parameters and selection basis of the device are given. Finally, the corresponding simulation model is built and verified with PSCAD software. Compared with the conventional DCCB scheme, the fault current is reduced by 48.6%; the absorbed energy, turn-off current and turn-off time of the arrester are reduced by 54.8%, 52.4% and 0.8 ms, respectively. Therefore, the new MP-DCCB has good reliability and economy, and the simulation results verify that the new topology scheme of power electronic multi-port HVDC circuit breaker with current limiting can be applied to the DC power grid.