Abstract: In order to minimize energy dissipation and obtain higher fault sensor nodes recognition rate for deploying multi-target monitoring wireless sensor networks (WSN), a fault-tolerant strategy for virtual sensor networks (VSN) based on statistical hypothesis testing was proposed. On the cluster tree based VSN architecture, the fault occurring was judged by checking the matching degree between local data reading sequence and event statistical characteristics. The simulation results showed that before any node energy exhaustion, the multi-event monitoring produced less unicast messages and more multicast messages than single-event monitoring. In addition, the proposed strategy can maintain the fault identification rate and event region monitoring probability at the satisfactory level with increase of the sensor nodes fault probability.