As the fault isolation device of the DC system，the HVDC circuit breaker plays a pivotal role in ensuring the reliable and stable operation of the DC grid. Aimed at the current shortcomings of high-voltage DC circuit breakers in terms of energy consumption，current limitation and rapidity, an improved capacitive commutation DC circuit breaker topology with current limiting function was proposed. Firstly, the principle of this topology was introduced in detail；With the 320kV DC system as the background，a circuit breaker model was built with electromagnetic transient simulation software for simulation，and finally compared with two traditional circuit breakers. The results show that, compared with other solutions, the circuit breaker has the following current limitation, the current limiting device is quickly put into operation after a fault occurs, and the fault current is quickly removed, which reduces the power electronic current stress while meeting the system's requirements for the rapidity of the circuit breaker; In terms of cost, the use of power electronic devices has been significantly reduced, which has good economy; in terms of lightning arrester energy absorption, the capacitor converter unit increases the resistance RC to advance the action time of the arrester, effectively reducing the energy absorption of the arrester.