High-voltage DC circuit breaker is one of the core equipment in multi-terminal DC transmission and DC grid technology.Existing DC circuit breakers based on capacitors are compared and analyzed in this paper,and advantages,disadvantages and applications of them are also pointed out.Then,an assembly DC circuit breaker based on pre-charged capacitors is proposed.The topology,working principle and control strategy of the proposed scheme are described in detail.Besides,the feasibility and effectiveness are validated by building a three-terminal ring DC model in PLECS.Finally,future research directions and problems to be solved for DC circuit breaker based on capacitors are pointed out.