Temporary short-circuit accidents of transmission lines will increase greatly in ±500 kV MMC-HVDC overhead transmission system, which need the DC circuit breakers (DCCBs) reclose to ensure the reliability of power supply. However, the transient operation characteristics for reclosing of DCCB are not yet clear. A ±500 kV pseudo bipolar MMC-HVDC overhead transmission system model is established, which includes the key equipment of converter station and the hybrid DCCB. The impact of the electromagnetic transient characteristics and key parameters of hybrid DCCB on the breaking and reclosing characteristics during the breaking and reclosing process is studied when a single pole occurs short circuit fault to ground. The simulation results show that the hybrid DCCBs could cut off the fault in a short time (less than 5 ms). Because the converter valve is not locked, the current of valve side of converter transformer would not reduce to 0 after the breaking of DCCB. After 150 ms of fault deionization, the current of valve side of converter transformer and the pole voltage would rise to the rated operating condition in 200 ms with oscillating condition. In addition, the breaking performance of DCCB reduces with the increasing of the capacitance of RCD branch, while the current transfer rate of solid branch and mechanical branch is not related to the capacitance of RCD branch. The results of this paper can provide the corresponding data reference for the performance check of circuit breaker of ±500 kV MMC-HVDC overhead transmission lines.