Aiming at the dynamic characteristics of topological structure for wireless sensor network and the fault-tolerant requirement of target detection by means of demand analysis to the network node characteristics network model and the wireless channel model some definitions and related mathematical model are given.On which basis a fault tolerant target detection and localization strategy in the presence collaborative sensor network is proposed which is composed of 3 phases as target region monitoring target monitoring and positioning and base station communication positioning.The principle of the method is that the target signal intensity received by sensor node is taken as the observation value and the average of observation value sequence of the surrounding nodes as local observation through local information exchange.Thus the qualified and excellent sensor nodes and the base station node communication are selected.Finally the target is localized precisely through two types of sensor node with good fault-tolerant performance and positioning accuracy.The simulation results verify the correctness and effectiveness of the proposed method from fault-tolerant ability evaluation and positioning accuracy.