Abstract: The DC transmission and distribution network provides a solution to the problems of large-scale and high-proportion renewable energy grid connection and large-capacity long-distance power transmission, and it is an important development direction for building a new power system dominated by renewable energy. The DC circuit breaker can quickly interrupt the fault current and effectively isolate the fault, and it is one of the key equipment to ensure the reliable operation of the DC transmission and distribution network. However, the current DC circuit breaker still has problems such as limited breaking current capacity and high price. This paper proposes a novel DC circuit breaker topology with controlled active oscillation, expounds its topology composition, breaking and closing principles, and completes the mathematical analysis of parameter design and the study of the influence laws. A 10kV controlled active oscillation DC circuit breaker prototype is developed, and the bidirectional current breaking test of rated current and fault current is carried out, which verifies the correctness of the proposed topology design and the feasibility of engineering application.