The fault current limiting in high-voltage dc (HVdc) grids is critical to reducing the breaking stress of dc circuit breaker and improving the breaking reliability. However, the existing HVdc circuit breakers rarely consider the rapid limiting of fault current in the breaking process. In this article, a novel HVdc circuit breaker integrating current commutation and damping is presented, which can realize fast current limiting and interruption while preserving large breaking capability and low cost. Simulation analysis of current commutation capability is carried out to determine the optimal parameters in the current damping module. Then, the fault current breaking performance of the proposed HVdc breaker is evaluated and compared with conventional hybrid HVdc breaker theoretically. Finally, a low-power prototype of the current damping dc breaker is built and tested to verify the validity of the proposed topology.