Wireless sensor networks（WSNs）boundary node detection is a fundamental problem for sensor applications.In order to reduce communication traffic and improve accuracy of the boundary node detection

design an improved boundary detection algorithm（ABRSN-TM）

the algorithm uses network latitude line to replace the shortest path tree to detect network hole structure;when number of holes in the network is much more

construct multiple rings surround a single hole in the network;introduce node dynamic replacement method on the ring

the ring is converted to network boundary

thereby reduce amount of exchange data

improve accuracy and timeliness of boundary node detection.The experimental results show the effectiveness of algorithm in recognition accuracy and detection speed.