Abstract: In recent years, with the rapid development of optical fiber communication network tapping technology, optical fiber communication security is facing new challenges. There are a number of known tapping methods of extracting or injecting information into a fiber link, while avoiding detection. Therefore, it is necessary to study optical fiber network tapping technology and its defensive measures. In this paper, the tapping cases in recent years were summarized. Optical fiber network tapping methods, both invasive and non-intrusive, were introduced. Optical fiber network security myths were analyzed. Finally, some measures to prevent fiber tapping or to nullify the significance of information tapped from fiber were also discussed.