The fault transient of multi-terminal DC power grid develops very fast, so it is necessary to con-figure current-limiting reactor to restrain the rise of fault current in practical engineering. However, configurations of current-limiting reactor will not be only narrow the fault current but impact on non-fault part. Therefore, configurations of current-limiting reactor in multi-terminal HVDC transmission system are considered in this paper. Firstly, in this paper, the fault calculation model of multi-terminal dc transmission sys-tem is established, and the calculation method of system state quantity including each action stage of circuit breaker is given. Then, this paper analyses the problems that are considered in the configuration of a current limiting reactor in multi-terminal HVDC transmission system. Finally, taking four-terminal HVDC transmission system as an example, the fault process of the dc system under different current-limiting re-actor configurations is simulated and calculated. Based on the calculation results, the influence of the maximum fault current of current-limiting reactor to a systems, the blocking condition of converter station, overvoltage of dc bus and decay time of overcurrent is analyzed.