Because　of　its　small,　flexibility,　low　cost　and　unattended,　wireless　sensor　networks　(WSNs)　are　widely　used　in　environmental　monitor,　healthcare,　smart　home,　military　fields,　and　so　on.　The　faults　are　common　due　to　the　bad　environment　and　unattended.　In　order　to　ensure　WSNs’　service　is　normal,　it　is　necessary　to　detect　the　faults　and　locate　the　faulty　sensors.　In　this　paper,　the　basic　method　of　fault　localisation　using　active　probing　is　studied,　the　key　problems　of　active　probing　are　analysed,　and　some　effective　solutions　to　these　problems　are　provided.　Firstly,　based　on　adjacent　matrix,　probe　stations　are　selected,　and　designed　a　maximal　greedy　algorithm　to　minimise　probe　sets.　Secondly,　binary　search　method　is　used　to　locate　the　faulty　sensor　quickly.　Lastly,　an　algorithm　to　identify　the　faulty　sensors　is　proposed　and　evaluated.　Fault　detection　precision　is　very　high,　and　the　implementation　complexity　of　the　algorithm　is　very　low,　easily　implemented　in　hardware.　Copyright　©　2017　Inderscience　Enterprises　Ltd.