Abstract: In order to overcome the weaknesses such as complexity of blocks scheduling algorithm and downloading stability of the popular BitTorrent system,a method to solve these weaknesses with network coding is put forward.NC-BT system based on network coding is designed and implemented.In actual network environment,the downloading performance of NC-BT is test and the result show that this scheme based on network coding can solve the existing problems of BitTorrent system.It can enhance the robustness of system and reduce the complexity of the scheduling algorithm.