A hybrid HVDC system based on the modular multilevel converter integrated with DC circuit breaker (IDCB-MMC) and line commutated converter (LCC) is proposed. When DC short-circuit fault occurs, by coordinating the operation of the converter and the DC circuit breaker, the DC fault current can be forced to transfer to the energy absorbing branches which are parallel connected across the DC bus. Therefore, the bulky and costly solid power electronics switch branch in conventinal hybrid HVDC breaker can be discarded. The LCC can clear the DC fault current by switching into the inverter mode. Simulations are carried out on one pole of a two-terminal 1 000 MW/±320 kV LCC-MMC hybrid HVDC system. The simulation results show that the DC fault current can be cleared by the IDCB-MMC and the power transimission can be automatically recovered. Simulation results also verify the feasiblity of the hybrid HVDC system composed of LCC and IDCB-MMC.