Focusing on the unreliable sensing phenomenon in wireless sensor networks and its impact on target-tracking accuracy, this paper first analyzes the uncertain area and its boundaries. Then the monitor area can be divided into faces by these uncertain boundaries and each face has an identical signature vector. On the other hand, for each target localization, any pair-wise nodes' RSS is ordinal or flipped can be determined by multiple grouping samplings and the sampling vector is built. Hence, the Fault-Tolerant Target-Tracking (FTTT) strategy is proposed, which transforms the tracking problem into a vector matching process in order to improve the tracking flexibility, increase the tracking accuracy and reduce the influence of in-the-filed factors. In addition, a heuristic matching algorithm is introduced to reduce the computational complexity. Results have shown that FTTT is more flexible and has higher tracking accuracy than congenerous methods.