Active distribution network (ADN) is a solution for power system with interconnection of distributed energy resources (DER), which may change the network operation and power flow of traditional power distribution network. However, in some circumstances the malfunction of protection and feeder automation in distribution network occurs due to the uncertain bidirectional power flow. Therefore, a novel method of fault location, isolation, and service restoration (FLISR) for ADN based on distributed processing is proposed in this paper. The differential-activated algorithm based on synchronous sampling for feeder fault location and isolation is studied, and a framework of fault restoration is established for ADN. Finally, the effectiveness of the proposed algorithm is verified via computer simulation of a case study for active distributed power system.