When a bus short circuit fault occurs in DC system, the fault current will rise rapidly. At present, the bus protection of the DC distribution network basically refers to the AC protection scheme, and the operation time is long, which is not conducive to the rapid isolation of the DC fault. In order to achieve reliable and fast protection of bus faults in DC distribution systems while ensuring economy, firstly the fault characteristics of the bus distribution of the DC distribution network are analyzed, and then the bus protection wiring scheme, protection algorithm and resource allocation of the DC distribution network are studied. Methods or recommendations for differential currents are directly collected by DC transformers, using current rate-of-change algorithms, hierarchically processing data, different exit relays and so on, which the effectiveness is verified by the real time digital simulator(RTDS). The proposed method can effectively improve the reliability and rapidity of bus protection of DC power distribution system as well as balancing economics.