Abstract: Aiming at the difficulty of fault isolation caused by large short-circuit fault current and no natural zero crossing of current in flexible direct distribution network, a hybrid capacitor-assisted circuit breaker is proposed. The circuit breaker possesses a two-stage current limiting structure. The low-resistance current limiting module is used to quickly limit the fault current in the initial stage and achieve the fault-current transfer. The high-resistance current limiting module is used to ensure the effective isolation. It can play a current limiting role before the fault line is identified. Compared with the typical method, the capacitor-assisted module can limit the development of the initial fault current and greatly reduce the peak current value of the main-breaker branch, and it has minimum impact on the main branch during the normal operation. Finally, a six-terminal DC distribution network is established by PSCAD/EMTDC for simulation analysis, and results show that the proposed scheme can significantly limit the fault current and meet both the economy and practicality.