In order to solve problems—— high cost and poor current limiting effect in most conventional hybrid DC circuit breaker, this paper proposes an assembly DC circuit breaker based on pre-charged capacitors. It mainly includes converter-part and line-part, both of which consist of pre-charged capacitors. Converter-part is installed on DC outlet side of converter station in DC grid, and line-part is on each DC transmission line. This hybrid breaker provides the arc-less breaking condition to mechanical breaker branch through pre-charged voltage of capacitors and can suppress fault current effectively. The topology, working principle, control strategy and comparison between the proposed and existing schemes are de-scribed in detail. Besides, the feasibility and effectiveness are validated by building a three-terminal DC model in PLECS. The results show that the proposed DC breaker can not only cut off the DC fault line, but also avoid collapse of bus voltage, ensuring the normal operation of non-faulty lines. Especially in future multi-terminal DC system, the shared converter-part will greatly save the equipment cost due to the common part at the converter site.