A new target tracking method based on pyroelectric infrared (IR) sensor network is presented in this paper.Large regions can be monitored in real time,and a tar get can be also detected and autonomously tracked by the pyroelectric infrared sensor network.In this met hod,instead of modulation of IR radiation by Fresnel lens which is complicated and with small d etection area,the pyroelectric sensor uses infrared lens as its optical module which has a l ong detection distance and is more convenient for signal processing.With this new method,the p yroelectric infrared sensor swings backward and forward in the range of 0°-90°,w hich has a large detection area and high sensitivity.By collecting and analyzing the characteristics of the sig nal output from the dynamic pyroelectric infrared sensor,angle information of the target can be obt ained.The target information can be accurately extracted by using frame difference method.Inform ation fusion of multiple nodes can achieve localization and tracking of the moving target by usi ng the sensor network target localization model.The method is an effective solution to the contradict ions between distance and angle detected by pyroelectric infrared sensor.The experimental re sults demonstrate that the proposed method has feasibility in detection range,s ensitivity and locating accuracy.