Abstract: With the development of urban distribution network, power users’ demand for DC distribution system is increasing. In order to study the development prospect of DC system, this paper discusses the reliability of DC distribution network. Firstly, this paper introduces the characteristics of DC distribution system, and summarizes the main structures. Then, the reliability assessment model of power electronic equipment is established, and the reliability parameters of redundant components are calculated by using k/n(G) and Markov chain model. The reliability index of DC distribution network is calculated with the minimum cut set method. Finally, the IEEE RBTS Bus5 system is modified to calculate and compare the reliability indices of different distribution networks. The results show that the reliability of DC distribution network is limited by the reliability of equipment, and the reliability of DC system can be improved with the increasing proportion of DC load. In the future, with the improvement of power electronic equipment and the increase of DC load, the reliability of DC distribution network will be better than that of AC distribution network.