Abstract: To prevent the various construction operations in urban rail transit control protection zone from affecting tunnel structure safety, a tunnel environment vibration monitoring system is needed to provide timely early-warning of potential hazards. The sensing principle and vibration signal acquisition and analysis methods of tunnel environment vibration monitoring system based on distributed optical fiber are introduced. Through field experiments, the vibration signals collected by the tunnel environment vibration monitoring system based on distributed optical fiber are studied and analyzed under various working conditions such as manual tapping, train operation, ground vehicle driving, and ground construction operations. The results show that the above monitoring system has relatively high detection sensitivity for micro-vibration events, and can distinguish different types of vibration signals through feature analysis of time-domain, frequency-domain and energy map, thus tunnel structure safety status is effectively monitored, serving the purpose of early warning.