In recent years, wireless sensor networks（WSN） are widely applied to three-dimensional monitoring, distributed monitoring, target tracking, space exploration, random distribution of measurement and other fields. Information transmission security of WSN is attracting more attention of researchers because of the wide applications of WSN for military purpose during the last decade,such as enemy reconnaissance,strength monitoring , etc. In this study, time reversal technique as a new technology was utilized to reduce probability that the signal were illegally detected in space and time domains. TR technique allows signals to be detected only at a specific time and specific space, while in the other time and space the signal will be very difficult to be detected . Thus, TR technology enhance the information security of WSN.