Extracellular traps (ETs) are extracellular structures composed of chromatin and granule proteins that bind and kill microorganisms. Presently, most of the research on ETs was focused on the study of their inducing factors and antibacterial activities. However, the study on the formation mechanism of ETs, and the function of mitochondria in releasing ETs are still in its infancy. To gain insight into the study, function and action mode were performed to characterize the ETs formation mechanism and elucidate the changes of mitochondria preliminarily. Additionally, ETs could be degraded by DNA enzyme. Those above provides helpful evidence for revealing the mechanism of ETs formation, action mode and elimination, deepening the cognition on the innate immune defense in invertebrates, as well as extending the immunology boundary of marine invertebrates.