Abstract: Delay Tolerant Network（DTN） is a class of networks that experience frequent and long-duration partitions due to sparse distribution of nodes.It has a broad prospect to new network applications for a better scalability，fault-tolerant and high performance.In DTNs path failure occurs frequently，sometimes even in a very short period routing is required to change，resulting in transmission delay and reception delay.And some well-known assumption of traditional networks are no longer true in DTNs.This paper presents path failure problems in DTNs.Traditional approaches are based on using precisely known network dynamics，which does not account for message losses.This paper describes the path failure process in DTNs when the path appears completely normal，completely failed and partially failed.Then a fault tolerant scheme to generate redundancy using erasure coding and full replication is adopted.This can greatly decrease the path failure probability.At last，a traffic DTN model is analyzed and evaluated.Results reveal the superiority of the scheme in comparison to other present schemes.