During normal operation of DC lines, the smoothing reactor can reduce current ripple. When a DC line fails, the rapid operation of the current limiting reactor can suppress the rising speed of the fault current. Therefore, considering the collaboration between current limiting reactors and smoothing reactors can not only suppress the rising speed of fault current, but also reduce the cutting capacity of DC circuit breakers. However, due to investment costs and system dynamic characteristics, the inductance capacity of smoothing reactors and current limiting reactors needs to be maintained within a reasonable range. Therefore, it is very meaningful to optimize the capacity configuration of smoothing reactors and current limiting reactors in the HVDC transmission system, while ensuring the current limiting capacity and reducing investment. Firstly, a fault equivalent model for the AC/DC hybrid power grid is established and the characteristics of the fault current at both ends when a bipolar short circuit occurs in the DC line are analyzed. Secondly, a mathematical model for optimizing the configuration of smoothing reactors and current limiting reactors is established. Finally, the proposed current limiting strategy is validated through MATLAB simulation experiments.