Abstract: Compared with the conventional nondestructive testing techniques, AE technique is more sensitive to dynamic defects. However, there are still a lot of challenges when using AE technique in practical applications, for example, the poor localization accuracy of AE sources and the interruption and influence caused by anisotropic problem of composite plate. Based on the above challenges, with the research targets of composite plate, this paper focuses on investigations of AE source localization algorithm and the propagation characteristics of AE signal in composite plate. Meanwhile, the traveling velocity omni-directional curves of AE signal in composite plate are also drawn. Eventually, AE source localization is realized by arranging AE sensor array in composite plate.